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

  #ifndef MM_SLAB_H
  #define MM_SLAB_H
  /*
   * Internal slab definitions
   */

  #ifdef CONFIG_SLOB
  /*
   * Common fields provided in kmem_cache by all slab allocators
   * This struct is either used directly by the allocator (SLOB)
   * or the allocator must include definitions for all fields
   * provided in kmem_cache_common in their definition of kmem_cache.
   *
   * Once we can do anonymous structs (C11 standard) we could put a
   * anonymous struct definition in these allocators so that the
   * separate allocations in the kmem_cache structure of SLAB and
   * SLUB is no longer needed.
   */
  struct kmem_cache {
  	unsigned int object_size;/* The original size of the object */
  	unsigned int size;	/* The aligned/padded/added on size  */
  	unsigned int align;	/* Alignment as calculated */

  	slab_flags_t flags;	/* Active flags on the slab */

  	unsigned int useroffset;/* Usercopy region offset */
  	unsigned int usersize;	/* Usercopy region size */

  	const char *name;	/* Slab name for sysfs */
  	int refcount;		/* Use counter */
  	void (*ctor)(void *);	/* Called on object slot creation */
  	struct list_head list;	/* List of all slab caches on the system */
  };

  #else /* !CONFIG_SLOB */
  
  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;
  			bool dying;
  		};
  		struct {
  			struct mem_cgroup *memcg;
  			struct list_head children_node;
  			struct list_head kmem_caches_node;
  			struct percpu_ref refcnt;
  
  			void (*work_fn)(struct kmem_cache *);
  			union {
  				struct rcu_head rcu_head;
  				struct work_struct work;
  			};
  		};
  	};
  };

  #endif /* CONFIG_SLOB */
  
  #ifdef CONFIG_SLAB
  #include <linux/slab_def.h>
  #endif
  
  #ifdef CONFIG_SLUB
  #include <linux/slub_def.h>
  #endif
  
  #include <linux/memcontrol.h>

  #include <linux/fault-inject.h>

  #include <linux/kasan.h>
  #include <linux/kmemleak.h>

  #include <linux/random.h>

  #include <linux/sched/mm.h>

  /*
   * State of the slab allocator.
   *
   * This is used to describe the states of the allocator during bootup.
   * Allocators use this to gradually bootstrap themselves. Most allocators
   * have the problem that the structures used for managing slab caches are
   * allocated from slab caches themselves.
   */
  enum slab_state {
  	DOWN,			/* No slab functionality yet */
  	PARTIAL,		/* SLUB: kmem_cache_node available */

  	PARTIAL_NODE,		/* SLAB: kmalloc size for node struct available */

  	UP,			/* Slab caches usable but not all extras yet */
  	FULL			/* Everything is working */
  };
  
  extern enum slab_state slab_state;

  /* The slab cache mutex protects the management structures during changes */
  extern struct mutex slab_mutex;

  
  /* The list of all slab caches on the system */

  extern struct list_head slab_caches;

  /* The slab cache that manages slab cache information */
  extern struct kmem_cache *kmem_cache;

  /* A table of kmalloc cache names and sizes */
  extern const struct kmalloc_info_struct {
  	const char *name;

  	unsigned int size;

  } kmalloc_info[];

  #ifndef CONFIG_SLOB
  /* Kmalloc array related functions */

  void setup_kmalloc_cache_index_table(void);

  void create_kmalloc_caches(slab_flags_t);

  
  /* Find the kmalloc slab corresponding for a certain size */
  struct kmem_cache *kmalloc_slab(size_t, gfp_t);

  #endif

  /* Functions provided by the slab allocators */

  int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);

  struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
  			slab_flags_t flags, unsigned int useroffset,
  			unsigned int usersize);

  extern void create_boot_cache(struct kmem_cache *, const char *name,

  			unsigned int size, slab_flags_t flags,
  			unsigned int useroffset, unsigned int usersize);

  int slab_unmergeable(struct kmem_cache *s);

  struct kmem_cache *find_mergeable(unsigned size, unsigned align,

  		slab_flags_t flags, const char *name, void (*ctor)(void *));

  #ifndef CONFIG_SLOB

  struct kmem_cache *

  __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,

  		   slab_flags_t flags, void (*ctor)(void *));

  slab_flags_t kmem_cache_flags(unsigned int object_size,

  	slab_flags_t flags, const char *name,

  	void (*ctor)(void *));

  #else

  static inline struct kmem_cache *

  __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,

  		   slab_flags_t flags, void (*ctor)(void *))

  { return NULL; }

  static inline slab_flags_t kmem_cache_flags(unsigned int object_size,

  	slab_flags_t flags, const char *name,

  	void (*ctor)(void *))
  {
  	return flags;
  }

  #endif

  /* Legal flag mask for kmem_cache_create(), for various configurations */

  #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
  			 SLAB_CACHE_DMA32 | SLAB_PANIC | \

  			 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )

  
  #if defined(CONFIG_DEBUG_SLAB)
  #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
  #elif defined(CONFIG_SLUB_DEBUG)
  #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \

  			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)

  #else
  #define SLAB_DEBUG_FLAGS (0)
  #endif
  
  #if defined(CONFIG_SLAB)
  #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \

  			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \

  			  SLAB_ACCOUNT)

  #elif defined(CONFIG_SLUB)
  #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \

  			  SLAB_TEMPORARY | SLAB_ACCOUNT)

  #else
  #define SLAB_CACHE_FLAGS (0)
  #endif

  /* Common flags available with current configuration */

  #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)

  /* Common flags permitted for kmem_cache_create */
  #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
  			      SLAB_RED_ZONE | \
  			      SLAB_POISON | \
  			      SLAB_STORE_USER | \
  			      SLAB_TRACE | \
  			      SLAB_CONSISTENCY_CHECKS | \
  			      SLAB_MEM_SPREAD | \
  			      SLAB_NOLEAKTRACE | \
  			      SLAB_RECLAIM_ACCOUNT | \
  			      SLAB_TEMPORARY | \

  			      SLAB_ACCOUNT)

  bool __kmem_cache_empty(struct kmem_cache *);

  int __kmem_cache_shutdown(struct kmem_cache *);

  void __kmem_cache_release(struct kmem_cache *);

  int __kmem_cache_shrink(struct kmem_cache *);
  void __kmemcg_cache_deactivate(struct kmem_cache *s);

  void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s);

  void slab_kmem_cache_release(struct kmem_cache *);

  void kmem_cache_shrink_all(struct kmem_cache *s);

  struct seq_file;
  struct file;

  struct slabinfo {
  	unsigned long active_objs;
  	unsigned long num_objs;
  	unsigned long active_slabs;
  	unsigned long num_slabs;
  	unsigned long shared_avail;
  	unsigned int limit;
  	unsigned int batchcount;
  	unsigned int shared;
  	unsigned int objects_per_slab;
  	unsigned int cache_order;
  };
  
  void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
  void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);

  ssize_t slabinfo_write(struct file *file, const char __user *buffer,
  		       size_t count, loff_t *ppos);

  /*
   * Generic implementation of bulk operations
   * These are useful for situations in which the allocator cannot

   * perform optimizations. In that case segments of the object listed

   * may be allocated or freed using these operations.
   */
  void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);

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

  static inline int cache_vmstat_idx(struct kmem_cache *s)
  {
  	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
  		NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE;
  }

  #ifdef CONFIG_MEMCG_KMEM

  
  /* List of all root caches. */
  extern struct list_head		slab_root_caches;
  #define root_caches_node	memcg_params.__root_caches_node

  /*
   * Iterate over all memcg caches of the given root cache. The caller must hold
   * slab_mutex.
   */
  #define for_each_memcg_cache(iter, root) \

  	list_for_each_entry(iter, &(root)->memcg_params.children, \
  			    memcg_params.children_node)

  static inline bool is_root_cache(struct kmem_cache *s)
  {

  	return !s->memcg_params.root_cache;

  }

  static inline bool slab_equal_or_root(struct kmem_cache *s,

  				      struct kmem_cache *p)

  {

  	return p == s || p == s->memcg_params.root_cache;

  }

  
  /*
   * We use suffixes to the name in memcg because we can't have caches
   * created in the system with the same name. But when we print them
   * locally, better refer to them with the base name
   */
  static inline const char *cache_name(struct kmem_cache *s)
  {
  	if (!is_root_cache(s))

  		s = s->memcg_params.root_cache;

  	return s->name;
  }

  static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
  {
  	if (is_root_cache(s))
  		return s;

  	return s->memcg_params.root_cache;

  }

  /*
   * Expects a pointer to a slab page. Please note, that PageSlab() check
   * isn't sufficient, as it returns true also for tail compound slab pages,
   * which do not have slab_cache pointer set.

   * So this function assumes that the page can pass PageSlab() && !PageTail()
   * check.

   *
   * The kmem_cache can be reparented asynchronously. The caller must ensure
   * the memcg lifetime, e.g. by taking rcu_read_lock() or cgroup_mutex.

   */
  static inline struct mem_cgroup *memcg_from_slab_page(struct page *page)
  {
  	struct kmem_cache *s;
  
  	s = READ_ONCE(page->slab_cache);
  	if (s && !is_root_cache(s))

  		return READ_ONCE(s->memcg_params.memcg);

  
  	return NULL;
  }
  
  /*
   * Charge the slab page belonging to the non-root kmem_cache.
   * Can be called for non-root kmem_caches only.
   */

  static __always_inline int memcg_charge_slab(struct page *page,
  					     gfp_t gfp, int order,
  					     struct kmem_cache *s)

  {

  	struct mem_cgroup *memcg;
  	struct lruvec *lruvec;

  	int ret;

  	rcu_read_lock();
  	memcg = READ_ONCE(s->memcg_params.memcg);
  	while (memcg && !css_tryget_online(&memcg->css))
  		memcg = parent_mem_cgroup(memcg);
  	rcu_read_unlock();
  
  	if (unlikely(!memcg || mem_cgroup_is_root(memcg))) {
  		mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
  				    (1 << order));
  		percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);
  		return 0;
  	}

  	ret = memcg_kmem_charge_memcg(page, gfp, order, memcg);

  	if (ret)

  		goto out;

  	lruvec = mem_cgroup_lruvec(page_pgdat(page), memcg);
  	mod_lruvec_state(lruvec, cache_vmstat_idx(s), 1 << order);
  
  	/* transer try_charge() page references to kmem_cache */

  	percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);

  	css_put_many(&memcg->css, 1 << order);

  out:
  	css_put(&memcg->css);
  	return ret;

  }

  /*
   * Uncharge a slab page belonging to a non-root kmem_cache.
   * Can be called for non-root kmem_caches only.
   */

  static __always_inline void memcg_uncharge_slab(struct page *page, int order,
  						struct kmem_cache *s)
  {

  	struct mem_cgroup *memcg;
  	struct lruvec *lruvec;

  	rcu_read_lock();
  	memcg = READ_ONCE(s->memcg_params.memcg);
  	if (likely(!mem_cgroup_is_root(memcg))) {
  		lruvec = mem_cgroup_lruvec(page_pgdat(page), memcg);
  		mod_lruvec_state(lruvec, cache_vmstat_idx(s), -(1 << order));
  		memcg_kmem_uncharge_memcg(page, order, memcg);
  	} else {
  		mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
  				    -(1 << order));
  	}
  	rcu_read_unlock();

  
  	percpu_ref_put_many(&s->memcg_params.refcnt, 1 << order);

  }

  
  extern void slab_init_memcg_params(struct kmem_cache *);

  extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);

  #else /* CONFIG_MEMCG_KMEM */

  /* If !memcg, all caches are root. */
  #define slab_root_caches	slab_caches
  #define root_caches_node	list

  #define for_each_memcg_cache(iter, root) \
  	for ((void)(iter), (void)(root); 0; )

  static inline bool is_root_cache(struct kmem_cache *s)
  {
  	return true;
  }

  static inline bool slab_equal_or_root(struct kmem_cache *s,
  				      struct kmem_cache *p)
  {

  	return s == p;

  }

  
  static inline const char *cache_name(struct kmem_cache *s)
  {
  	return s->name;
  }

  static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
  {
  	return s;
  }

  static inline struct mem_cgroup *memcg_from_slab_page(struct page *page)
  {
  	return NULL;
  }

  static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
  				    struct kmem_cache *s)

  {
  	return 0;
  }

  static inline void memcg_uncharge_slab(struct page *page, int order,
  				       struct kmem_cache *s)
  {
  }

  static inline void slab_init_memcg_params(struct kmem_cache *s)
  {
  }

  static inline void memcg_link_cache(struct kmem_cache *s,
  				    struct mem_cgroup *memcg)

  {
  }

  #endif /* CONFIG_MEMCG_KMEM */

  static inline struct kmem_cache *virt_to_cache(const void *obj)
  {
  	struct page *page;
  
  	page = virt_to_head_page(obj);
  	if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!
  ",
  					__func__))
  		return NULL;
  	return page->slab_cache;
  }

  static __always_inline int charge_slab_page(struct page *page,
  					    gfp_t gfp, int order,
  					    struct kmem_cache *s)
  {

  	if (is_root_cache(s)) {
  		mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
  				    1 << order);
  		return 0;
  	}

  	return memcg_charge_slab(page, gfp, order, s);

  }
  
  static __always_inline void uncharge_slab_page(struct page *page, int order,
  					       struct kmem_cache *s)
  {

  	if (is_root_cache(s)) {
  		mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
  				    -(1 << order));
  		return;
  	}

  	memcg_uncharge_slab(page, order, s);
  }

  static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
  {
  	struct kmem_cache *cachep;

  
  	/*
  	 * When kmemcg is not being used, both assignments should return the
  	 * same value. but we don't want to pay the assignment price in that
  	 * case. If it is not compiled in, the compiler should be smart enough
  	 * to not do even the assignment. In that case, slab_equal_or_root
  	 * will also be a constant.
  	 */

  	if (!memcg_kmem_enabled() &&

  	    !IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&

  	    !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))

  		return s;

  	cachep = virt_to_cache(x);
  	WARN_ONCE(cachep && !slab_equal_or_root(cachep, s),

  		  "%s: Wrong slab cache. %s but object is from %s
  ",
  		  __func__, s->name, cachep->name);
  	return cachep;

  }

  static inline size_t slab_ksize(const struct kmem_cache *s)
  {
  #ifndef CONFIG_SLUB
  	return s->object_size;
  
  #else /* CONFIG_SLUB */
  # ifdef CONFIG_SLUB_DEBUG
  	/*
  	 * Debugging requires use of the padding between object
  	 * and whatever may come after it.
  	 */
  	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
  		return s->object_size;
  # endif

  	if (s->flags & SLAB_KASAN)
  		return s->object_size;

  	/*
  	 * If we have the need to store the freelist pointer
  	 * back there or track user information then we can
  	 * only use the space before that information.
  	 */

  	if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))

  		return s->inuse;
  	/*
  	 * Else we can use all the padding etc for the allocation
  	 */
  	return s->size;
  #endif
  }
  
  static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
  						     gfp_t flags)
  {
  	flags &= gfp_allowed_mask;

  
  	fs_reclaim_acquire(flags);
  	fs_reclaim_release(flags);

  	might_sleep_if(gfpflags_allow_blocking(flags));

  	if (should_failslab(s, flags))

  		return NULL;

  	if (memcg_kmem_enabled() &&
  	    ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
  		return memcg_kmem_get_cache(s);
  
  	return s;

  }
  
  static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
  					size_t size, void **p)
  {
  	size_t i;
  
  	flags &= gfp_allowed_mask;
  	for (i = 0; i < size; i++) {

  		p[i] = kasan_slab_alloc(s, p[i], flags);

  		/* As p[i] might get tagged, call kmemleak hook after KASAN. */

  		kmemleak_alloc_recursive(p[i], s->object_size, 1,

  					 s->flags, flags);

  	}

  
  	if (memcg_kmem_enabled())
  		memcg_kmem_put_cache(s);

  }

  #ifndef CONFIG_SLOB

  /*
   * The slab lists for all objects.
   */
  struct kmem_cache_node {
  	spinlock_t list_lock;
  
  #ifdef CONFIG_SLAB
  	struct list_head slabs_partial;	/* partial list first, better asm code */
  	struct list_head slabs_full;
  	struct list_head slabs_free;

  	unsigned long total_slabs;	/* length of all slab lists */
  	unsigned long free_slabs;	/* length of free slab list only */

  	unsigned long free_objects;
  	unsigned int free_limit;
  	unsigned int colour_next;	/* Per-node cache coloring */
  	struct array_cache *shared;	/* shared per node */

  	struct alien_cache **alien;	/* on other nodes */

  	unsigned long next_reap;	/* updated without locking */
  	int free_touched;		/* updated without locking */
  #endif
  
  #ifdef CONFIG_SLUB
  	unsigned long nr_partial;
  	struct list_head partial;
  #ifdef CONFIG_SLUB_DEBUG
  	atomic_long_t nr_slabs;
  	atomic_long_t total_objects;
  	struct list_head full;
  #endif
  #endif
  
  };

  static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
  {
  	return s->node[node];
  }
  
  /*
   * Iterator over all nodes. The body will be executed for each node that has
   * a kmem_cache_node structure allocated (which is true for all online nodes)
   */
  #define for_each_kmem_cache_node(__s, __node, __n) \

  	for (__node = 0; __node < nr_node_ids; __node++) \
  		 if ((__n = get_node(__s, __node)))

  
  #endif

  void *slab_start(struct seq_file *m, loff_t *pos);

  void *slab_next(struct seq_file *m, void *p, loff_t *pos);
  void slab_stop(struct seq_file *m, void *p);

  void *memcg_slab_start(struct seq_file *m, loff_t *pos);
  void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
  void memcg_slab_stop(struct seq_file *m, void *p);

  int memcg_slab_show(struct seq_file *m, void *p);

  #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
  void dump_unreclaimable_slab(void);
  #else
  static inline void dump_unreclaimable_slab(void)
  {
  }
  #endif

  void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);

  #ifdef CONFIG_SLAB_FREELIST_RANDOM
  int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
  			gfp_t gfp);
  void cache_random_seq_destroy(struct kmem_cache *cachep);
  #else
  static inline int cache_random_seq_create(struct kmem_cache *cachep,
  					unsigned int count, gfp_t gfp)
  {
  	return 0;
  }
  static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
  #endif /* CONFIG_SLAB_FREELIST_RANDOM */

  static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
  {
  	if (static_branch_unlikely(&init_on_alloc)) {
  		if (c->ctor)
  			return false;
  		if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
  			return flags & __GFP_ZERO;
  		return true;
  	}
  	return flags & __GFP_ZERO;
  }
  
  static inline bool slab_want_init_on_free(struct kmem_cache *c)
  {
  	if (static_branch_unlikely(&init_on_free))
  		return !(c->ctor ||
  			 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
  	return false;
  }

  #endif /* MM_SLAB_H */