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

  /*

   * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
   *

   * (C) SGI 2006, Christoph Lameter

   * 	Cleaned up and restructured to ease the addition of alternative
   * 	implementations of SLAB allocators.

   * (C) Linux Foundation 2008-2013
   *      Unified interface for all slab allocators

   */
  
  #ifndef _LINUX_SLAB_H
  #define	_LINUX_SLAB_H

  #include <linux/gfp.h>

  #include <linux/types.h>

  #include <linux/workqueue.h>

  /*
   * Flags to pass to kmem_cache_create().

   * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.

   */

  #define SLAB_CONSISTENCY_CHECKS	0x00000100UL	/* DEBUG: Perform (expensive) checks on alloc/free */

  #define SLAB_RED_ZONE		0x00000400UL	/* DEBUG: Red zone objs in a cache */
  #define SLAB_POISON		0x00000800UL	/* DEBUG: Poison objects */
  #define SLAB_HWCACHE_ALIGN	0x00002000UL	/* Align objs on cache lines */

  #define SLAB_CACHE_DMA		0x00004000UL	/* Use GFP_DMA memory */

  #define SLAB_STORE_USER		0x00010000UL	/* DEBUG: Store the last owner for bug hunting */

  #define SLAB_PANIC		0x00040000UL	/* Panic if kmem_cache_create() fails */

  /*

   * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!

   *
   * This delays freeing the SLAB page by a grace period, it does _NOT_
   * delay object freeing. This means that if you do kmem_cache_free()
   * that memory location is free to be reused at any time. Thus it may
   * be possible to see another object there in the same RCU grace period.
   *
   * This feature only ensures the memory location backing the object
   * stays valid, the trick to using this is relying on an independent
   * object validation pass. Something like:
   *
   *  rcu_read_lock()
   * again:
   *  obj = lockless_lookup(key);
   *  if (obj) {
   *    if (!try_get_ref(obj)) // might fail for free objects
   *      goto again;
   *
   *    if (obj->key != key) { // not the object we expected
   *      put_ref(obj);
   *      goto again;
   *    }
   *  }
   *  rcu_read_unlock();
   *

   * This is useful if we need to approach a kernel structure obliquely,
   * from its address obtained without the usual locking. We can lock
   * the structure to stabilize it and check it's still at the given address,
   * only if we can be sure that the memory has not been meanwhile reused
   * for some other kind of object (which our subsystem's lock might corrupt).
   *
   * rcu_read_lock before reading the address, then rcu_read_unlock after
   * taking the spinlock within the structure expected at that address.

   *
   * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.

   */

  #define SLAB_TYPESAFE_BY_RCU	0x00080000UL	/* Defer freeing slabs to RCU */

  #define SLAB_MEM_SPREAD		0x00100000UL	/* Spread some memory over cpuset */

  #define SLAB_TRACE		0x00200000UL	/* Trace allocations and frees */

  /* Flag to prevent checks on free */
  #ifdef CONFIG_DEBUG_OBJECTS
  # define SLAB_DEBUG_OBJECTS	0x00400000UL
  #else
  # define SLAB_DEBUG_OBJECTS	0x00000000UL
  #endif

  #define SLAB_NOLEAKTRACE	0x00800000UL	/* Avoid kmemleak tracing */

  #ifdef CONFIG_FAILSLAB
  # define SLAB_FAILSLAB		0x02000000UL	/* Fault injection mark */
  #else
  # define SLAB_FAILSLAB		0x00000000UL
  #endif

  #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)

  # define SLAB_ACCOUNT		0x04000000UL	/* Account to memcg */
  #else
  # define SLAB_ACCOUNT		0x00000000UL
  #endif

  #ifdef CONFIG_KASAN
  #define SLAB_KASAN		0x08000000UL
  #else
  #define SLAB_KASAN		0x00000000UL
  #endif

  /* The following flags affect the page allocator grouping pages by mobility */
  #define SLAB_RECLAIM_ACCOUNT	0x00020000UL		/* Objects are reclaimable */
  #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */

  /*

   * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
   *
   * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
   *
   * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
   * Both make kfree a no-op.
   */
  #define ZERO_SIZE_PTR ((void *)16)

  #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \

  				(unsigned long)ZERO_SIZE_PTR)

  #include <linux/kmemleak.h>

  #include <linux/kasan.h>

  struct mem_cgroup;

  /*

   * struct kmem_cache related prototypes
   */
  void __init kmem_cache_init(void);

  bool slab_is_available(void);

  struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,

  			unsigned long,

  			void (*)(void *));

  void kmem_cache_destroy(struct kmem_cache *);
  int kmem_cache_shrink(struct kmem_cache *);

  
  void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
  void memcg_deactivate_kmem_caches(struct mem_cgroup *);
  void memcg_destroy_kmem_caches(struct mem_cgroup *);

  /*
   * Please use this macro to create slab caches. Simply specify the
   * name of the structure and maybe some flags that are listed above.
   *
   * The alignment of the struct determines object alignment. If you
   * f.e. add ____cacheline_aligned_in_smp to the struct declaration
   * then the objects will be properly aligned in SMP configurations.
   */
  #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
  		sizeof(struct __struct), __alignof__(struct __struct),\

  		(__flags), NULL)

  /*

   * Common kmalloc functions provided by all allocators
   */
  void * __must_check __krealloc(const void *, size_t, gfp_t);
  void * __must_check krealloc(const void *, size_t, gfp_t);
  void kfree(const void *);
  void kzfree(const void *);
  size_t ksize(const void *);

  #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
  const char *__check_heap_object(const void *ptr, unsigned long n,
  				struct page *page);
  #else
  static inline const char *__check_heap_object(const void *ptr,
  					      unsigned long n,
  					      struct page *page)
  {
  	return NULL;
  }
  #endif

  /*
   * Some archs want to perform DMA into kmalloc caches and need a guaranteed
   * alignment larger than the alignment of a 64-bit integer.
   * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
   */
  #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
  #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
  #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
  #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
  #else
  #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
  #endif

  /*

   * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
   * Intended for arches that get misalignment faults even for 64 bit integer
   * aligned buffers.
   */
  #ifndef ARCH_SLAB_MINALIGN
  #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
  #endif
  
  /*
   * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
   * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
   * aligned pointers.
   */
  #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
  #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
  #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
  
  /*

   * Kmalloc array related definitions
   */
  
  #ifdef CONFIG_SLAB
  /*
   * The largest kmalloc size supported by the SLAB allocators is

   * 32 megabyte (2^25) or the maximum allocatable page order if that is
   * less than 32 MB.
   *
   * WARNING: Its not easy to increase this value since the allocators have
   * to do various tricks to work around compiler limitations in order to
   * ensure proper constant folding.
   */

  #define KMALLOC_SHIFT_HIGH	((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
  				(MAX_ORDER + PAGE_SHIFT - 1) : 25)

  #define KMALLOC_SHIFT_MAX	KMALLOC_SHIFT_HIGH

  #ifndef KMALLOC_SHIFT_LOW

  #define KMALLOC_SHIFT_LOW	5

  #endif

  #endif
  
  #ifdef CONFIG_SLUB

  /*

   * SLUB directly allocates requests fitting in to an order-1 page
   * (PAGE_SIZE*2).  Larger requests are passed to the page allocator.

   */
  #define KMALLOC_SHIFT_HIGH	(PAGE_SHIFT + 1)

  #define KMALLOC_SHIFT_MAX	(MAX_ORDER + PAGE_SHIFT - 1)

  #ifndef KMALLOC_SHIFT_LOW

  #define KMALLOC_SHIFT_LOW	3
  #endif

  #endif

  #ifdef CONFIG_SLOB
  /*

   * SLOB passes all requests larger than one page to the page allocator.

   * No kmalloc array is necessary since objects of different sizes can
   * be allocated from the same page.
   */

  #define KMALLOC_SHIFT_HIGH	PAGE_SHIFT

  #define KMALLOC_SHIFT_MAX	(MAX_ORDER + PAGE_SHIFT - 1)

  #ifndef KMALLOC_SHIFT_LOW
  #define KMALLOC_SHIFT_LOW	3
  #endif
  #endif

  /* Maximum allocatable size */
  #define KMALLOC_MAX_SIZE	(1UL << KMALLOC_SHIFT_MAX)
  /* Maximum size for which we actually use a slab cache */
  #define KMALLOC_MAX_CACHE_SIZE	(1UL << KMALLOC_SHIFT_HIGH)
  /* Maximum order allocatable via the slab allocagtor */
  #define KMALLOC_MAX_ORDER	(KMALLOC_SHIFT_MAX - PAGE_SHIFT)

  /*

   * Kmalloc subsystem.
   */

  #ifndef KMALLOC_MIN_SIZE

  #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)

  #endif

  /*
   * This restriction comes from byte sized index implementation.
   * Page size is normally 2^12 bytes and, in this case, if we want to use
   * byte sized index which can represent 2^8 entries, the size of the object
   * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
   * If minimum size of kmalloc is less than 16, we use it as minimum object
   * size and give up to use byte sized index.
   */
  #define SLAB_OBJ_MIN_SIZE      (KMALLOC_MIN_SIZE < 16 ? \
                                 (KMALLOC_MIN_SIZE) : 16)

  #ifndef CONFIG_SLOB

  extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
  #ifdef CONFIG_ZONE_DMA
  extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
  #endif

  /*
   * Figure out which kmalloc slab an allocation of a certain size
   * belongs to.
   * 0 = zero alloc
   * 1 =  65 .. 96 bytes

   * 2 = 129 .. 192 bytes
   * n = 2^(n-1)+1 .. 2^n

   */
  static __always_inline int kmalloc_index(size_t size)
  {
  	if (!size)
  		return 0;
  
  	if (size <= KMALLOC_MIN_SIZE)
  		return KMALLOC_SHIFT_LOW;
  
  	if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
  		return 1;
  	if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
  		return 2;
  	if (size <=          8) return 3;
  	if (size <=         16) return 4;
  	if (size <=         32) return 5;
  	if (size <=         64) return 6;
  	if (size <=        128) return 7;
  	if (size <=        256) return 8;
  	if (size <=        512) return 9;
  	if (size <=       1024) return 10;
  	if (size <=   2 * 1024) return 11;
  	if (size <=   4 * 1024) return 12;
  	if (size <=   8 * 1024) return 13;
  	if (size <=  16 * 1024) return 14;
  	if (size <=  32 * 1024) return 15;
  	if (size <=  64 * 1024) return 16;
  	if (size <= 128 * 1024) return 17;
  	if (size <= 256 * 1024) return 18;
  	if (size <= 512 * 1024) return 19;
  	if (size <= 1024 * 1024) return 20;
  	if (size <=  2 * 1024 * 1024) return 21;
  	if (size <=  4 * 1024 * 1024) return 22;
  	if (size <=  8 * 1024 * 1024) return 23;
  	if (size <=  16 * 1024 * 1024) return 24;
  	if (size <=  32 * 1024 * 1024) return 25;
  	if (size <=  64 * 1024 * 1024) return 26;
  	BUG();
  
  	/* Will never be reached. Needed because the compiler may complain */
  	return -1;
  }

  #endif /* !CONFIG_SLOB */

  void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
  void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;

  void kmem_cache_free(struct kmem_cache *, void *);

  /*

   * Bulk allocation and freeing operations. These are accelerated in an

   * allocator specific way to avoid taking locks repeatedly or building
   * metadata structures unnecessarily.
   *
   * Note that interrupts must be enabled when calling these functions.
   */
  void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);

  int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);

  /*
   * Caller must not use kfree_bulk() on memory not originally allocated
   * by kmalloc(), because the SLOB allocator cannot handle this.
   */
  static __always_inline void kfree_bulk(size_t size, void **p)
  {
  	kmem_cache_free_bulk(NULL, size, p);
  }

  #ifdef CONFIG_NUMA

  void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
  void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;

  #else
  static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
  {
  	return __kmalloc(size, flags);
  }
  
  static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
  {
  	return kmem_cache_alloc(s, flags);
  }
  #endif
  
  #ifdef CONFIG_TRACING

  extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc;

  
  #ifdef CONFIG_NUMA
  extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
  					   gfp_t gfpflags,

  					   int node, size_t size) __assume_slab_alignment __malloc;

  #else
  static __always_inline void *
  kmem_cache_alloc_node_trace(struct kmem_cache *s,
  			      gfp_t gfpflags,
  			      int node, size_t size)
  {
  	return kmem_cache_alloc_trace(s, gfpflags, size);
  }
  #endif /* CONFIG_NUMA */
  
  #else /* CONFIG_TRACING */
  static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
  		gfp_t flags, size_t size)
  {

  	void *ret = kmem_cache_alloc(s, flags);

  	kasan_kmalloc(s, ret, size, flags);

  	return ret;

  }
  
  static __always_inline void *
  kmem_cache_alloc_node_trace(struct kmem_cache *s,
  			      gfp_t gfpflags,
  			      int node, size_t size)
  {

  	void *ret = kmem_cache_alloc_node(s, gfpflags, node);

  	kasan_kmalloc(s, ret, size, gfpflags);

  	return ret;

  }
  #endif /* CONFIG_TRACING */

  extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;

  
  #ifdef CONFIG_TRACING

  extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;

  #else
  static __always_inline void *
  kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
  {
  	return kmalloc_order(size, flags, order);
  }

  #endif

  static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
  {
  	unsigned int order = get_order(size);
  	return kmalloc_order_trace(size, flags, order);
  }
  
  /**
   * kmalloc - allocate memory
   * @size: how many bytes of memory are required.

   * @flags: the type of memory to allocate.

   *
   * kmalloc is the normal method of allocating memory
   * for objects smaller than page size in the kernel.

   *
   * The @flags argument may be one of:
   *
   * %GFP_USER - Allocate memory on behalf of user.  May sleep.
   *
   * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
   *
   * %GFP_ATOMIC - Allocation will not sleep.  May use emergency pools.
   *   For example, use this inside interrupt handlers.
   *
   * %GFP_HIGHUSER - Allocate pages from high memory.
   *
   * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
   *
   * %GFP_NOFS - Do not make any fs calls while trying to get memory.
   *
   * %GFP_NOWAIT - Allocation will not sleep.
   *

   * %__GFP_THISNODE - Allocate node-local memory only.

   *
   * %GFP_DMA - Allocation suitable for DMA.
   *   Should only be used for kmalloc() caches. Otherwise, use a
   *   slab created with SLAB_DMA.
   *
   * Also it is possible to set different flags by OR'ing
   * in one or more of the following additional @flags:
   *
   * %__GFP_COLD - Request cache-cold pages instead of
   *   trying to return cache-warm pages.
   *
   * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
   *
   * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
   *   (think twice before using).
   *
   * %__GFP_NORETRY - If memory is not immediately available,
   *   then give up at once.
   *
   * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
   *

   * %__GFP_RETRY_MAYFAIL - Try really hard to succeed the allocation but fail
   *   eventually.

   *
   * There are other flags available as well, but these are not intended
   * for general use, and so are not documented here. For a full list of
   * potential flags, always refer to linux/gfp.h.

   */
  static __always_inline void *kmalloc(size_t size, gfp_t flags)
  {
  	if (__builtin_constant_p(size)) {
  		if (size > KMALLOC_MAX_CACHE_SIZE)
  			return kmalloc_large(size, flags);
  #ifndef CONFIG_SLOB
  		if (!(flags & GFP_DMA)) {
  			int index = kmalloc_index(size);
  
  			if (!index)
  				return ZERO_SIZE_PTR;
  
  			return kmem_cache_alloc_trace(kmalloc_caches[index],
  					flags, size);
  		}
  #endif
  	}
  	return __kmalloc(size, flags);
  }

  /*
   * Determine size used for the nth kmalloc cache.
   * return size or 0 if a kmalloc cache for that
   * size does not exist
   */
  static __always_inline int kmalloc_size(int n)
  {

  #ifndef CONFIG_SLOB

  	if (n > 2)
  		return 1 << n;
  
  	if (n == 1 && KMALLOC_MIN_SIZE <= 32)
  		return 96;
  
  	if (n == 2 && KMALLOC_MIN_SIZE <= 64)
  		return 192;

  #endif

  	return 0;
  }

  static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
  {
  #ifndef CONFIG_SLOB
  	if (__builtin_constant_p(size) &&

  		size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {

  		int i = kmalloc_index(size);
  
  		if (!i)
  			return ZERO_SIZE_PTR;
  
  		return kmem_cache_alloc_node_trace(kmalloc_caches[i],
  						flags, node, size);
  	}
  #endif
  	return __kmalloc_node(size, flags, node);
  }

  struct memcg_cache_array {
  	struct rcu_head rcu;
  	struct kmem_cache *entries[0];
  };

  /*

   * This is the main placeholder for memcg-related information in kmem caches.

   * Both the root cache and the child caches will have it. For the root cache,
   * this will hold a dynamically allocated array large enough to hold

   * information about the currently limited memcgs in the system. To allow the
   * array to be accessed without taking any locks, on relocation we free the old
   * version only after a grace period.

   *

   * Root and child caches hold different metadata.

   *

   * @root_cache:	Common to root and child caches.  NULL for root, pointer to
   *		the root cache for children.

   *

   * The following fields are specific to root caches.
   *
   * @memcg_caches: kmemcg ID indexed table of child caches.  This table is
   *		used to index child cachces during allocation and cleared
   *		early during shutdown.
   *

   * @root_caches_node: List node for slab_root_caches list.
   *

   * @children:	List of all child caches.  While the child caches are also
   *		reachable through @memcg_caches, a child cache remains on
   *		this list until it is actually destroyed.
   *
   * The following fields are specific to child caches.
   *
   * @memcg:	Pointer to the memcg this cache belongs to.
   *
   * @children_node: List node for @root_cache->children list.

   *
   * @kmem_caches_node: List node for @memcg->kmem_caches list.

   */
  struct memcg_cache_params {

  	struct kmem_cache *root_cache;

  	union {

  		struct {
  			struct memcg_cache_array __rcu *memcg_caches;

  			struct list_head __root_caches_node;

  			struct list_head children;
  		};

  		struct {
  			struct mem_cgroup *memcg;

  			struct list_head children_node;

  			struct list_head kmem_caches_node;

  
  			void (*deact_fn)(struct kmem_cache *);
  			union {
  				struct rcu_head deact_rcu_head;
  				struct work_struct deact_work;
  			};

  		};

  	};
  };

  int memcg_update_all_caches(int num_memcgs);

  /**

   * kmalloc_array - allocate memory for an array.
   * @n: number of elements.
   * @size: element size.
   * @flags: the type of memory to allocate (see kmalloc).

   */

  static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)

  {

  	if (size != 0 && n > SIZE_MAX / size)

  		return NULL;

  	if (__builtin_constant_p(n) && __builtin_constant_p(size))
  		return kmalloc(n * size, flags);

  	return __kmalloc(n * size, flags);
  }
  
  /**
   * kcalloc - allocate memory for an array. The memory is set to zero.
   * @n: number of elements.
   * @size: element size.
   * @flags: the type of memory to allocate (see kmalloc).
   */
  static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
  {
  	return kmalloc_array(n, size, flags | __GFP_ZERO);

  }

  /*
   * kmalloc_track_caller is a special version of kmalloc that records the
   * calling function of the routine calling it for slab leak tracking instead
   * of just the calling function (confusing, eh?).
   * It's useful when the call to kmalloc comes from a widely-used standard
   * allocator where we care about the real place the memory allocation
   * request comes from.
   */

  extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);

  #define kmalloc_track_caller(size, flags) \

  	__kmalloc_track_caller(size, flags, _RET_IP_)

  #ifdef CONFIG_NUMA

  extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);

  #define kmalloc_node_track_caller(size, flags, node) \
  	__kmalloc_node_track_caller(size, flags, node, \

  			_RET_IP_)

  #else /* CONFIG_NUMA */

  
  #define kmalloc_node_track_caller(size, flags, node) \
  	kmalloc_track_caller(size, flags)

  #endif /* CONFIG_NUMA */

  /*
   * Shortcuts
   */
  static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
  {
  	return kmem_cache_alloc(k, flags | __GFP_ZERO);
  }
  
  /**
   * kzalloc - allocate memory. The memory is set to zero.
   * @size: how many bytes of memory are required.
   * @flags: the type of memory to allocate (see kmalloc).
   */
  static inline void *kzalloc(size_t size, gfp_t flags)
  {
  	return kmalloc(size, flags | __GFP_ZERO);
  }

  /**
   * kzalloc_node - allocate zeroed memory from a particular memory node.
   * @size: how many bytes of memory are required.
   * @flags: the type of memory to allocate (see kmalloc).
   * @node: memory node from which to allocate
   */
  static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
  {
  	return kmalloc_node(size, flags | __GFP_ZERO, node);
  }

  unsigned int kmem_cache_size(struct kmem_cache *s);

  void __init kmem_cache_init_late(void);

  #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
  int slab_prepare_cpu(unsigned int cpu);
  int slab_dead_cpu(unsigned int cpu);
  #else
  #define slab_prepare_cpu	NULL
  #define slab_dead_cpu		NULL
  #endif

  #endif	/* _LINUX_SLAB_H */