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

/*
 * 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_ARRAYCACHE,     /* SLAB: kmalloc size for arraycache 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;

unsigned long calculate_alignment(unsigned long flags,
                unsigned long align, unsigned long size);

#ifndef CONFIG_SLOB
/* Kmalloc array related functions */
void create_kmalloc_caches(unsigned long);

/* 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 */
extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);

extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
                        unsigned long flags);
extern void create_boot_cache(struct kmem_cache *, const char *name,
                        size_t size, unsigned long flags);

struct mem_cgroup;
#ifdef CONFIG_SLUB
struct kmem_cache *
__kmem_cache_alias(const char *name, size_t size, size_t align,
                   unsigned long flags, void (*ctor)(void *));
#else
static inline struct kmem_cache *
__kmem_cache_alias(const char *name, size_t size, size_t align,
                   unsigned long flags, void (*ctor)(void *))
{ return NULL; }
#endif


/* Legal flag mask for kmem_cache_create(), for various configurations */
#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
                         SLAB_DESTROY_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_NOTRACK | SLAB_ACCOUNT)
#elif defined(CONFIG_SLUB)
#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
                          SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT)
#else
#define SLAB_CACHE_FLAGS (0)
#endif

#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)

int __kmem_cache_shutdown(struct kmem_cache *);

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 objecct 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 **);

#ifdef CONFIG_MEMCG_KMEM
static inline bool is_root_cache(struct kmem_cache *s)
{
        return !s->memcg_params || s->memcg_params->is_root_cache;
}

static inline void memcg_bind_pages(struct kmem_cache *s, int order)
{
        if (!is_root_cache(s))
                atomic_add(1 << order, &s->memcg_params->nr_pages);
}

static inline void memcg_release_pages(struct kmem_cache *s, int order)
{
        if (!is_root_cache(s))
                atomic_sub(1 << order, &s->memcg_params->nr_pages);
}

static inline bool slab_equal_or_root(struct kmem_cache *s,
                                        struct kmem_cache *p)
{
        return (p == s) ||
                (s->memcg_params && (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))
                return s->memcg_params->root_cache->name;
        return s->name;
}

/*
 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
 * That said the caller must assure the memcg's cache won't go away. Since once
 * created a memcg's cache is destroyed only along with the root cache, it is
 * true if we are going to allocate from the cache or hold a reference to the
 * root cache by other means. Otherwise, we should hold either the slab_mutex
 * or the memcg's slab_caches_mutex while calling this function and accessing
 * the returned value.
 */
static inline struct kmem_cache *
cache_from_memcg_idx(struct kmem_cache *s, int idx)
{
        struct kmem_cache *cachep;
        struct memcg_cache_params *params;

        if (!s->memcg_params)
                return NULL;

        rcu_read_lock();
        params = rcu_dereference(s->memcg_params);
        cachep = params->memcg_caches[idx];
        rcu_read_unlock();

        /*
         * Make sure we will access the up-to-date value. The code updating
         * memcg_caches issues a write barrier to match this (see
         * memcg_register_cache()).
         */
        smp_read_barrier_depends();
        return cachep;
}

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;
}

static __always_inline int memcg_charge_slab(struct kmem_cache *s,
                                             gfp_t gfp, int order)
{
        if (!memcg_kmem_enabled())
                return 0;
        if (is_root_cache(s))
                return 0;
        return memcg_charge_kmem(s->memcg_params->memcg, gfp, 1 << order);
}

static __always_inline void memcg_uncharge_slab(struct kmem_cache *s, int order)
{
        if (!memcg_kmem_enabled())
                return;
        if (is_root_cache(s))
                return;
        memcg_uncharge_kmem(s->memcg_params->memcg, 1 << order);
}
#else
static inline bool is_root_cache(struct kmem_cache *s)
{
        return true;
}

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

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

static inline bool slab_equal_or_root(struct kmem_cache *s,
                                      struct kmem_cache *p)
{
        return true;
}

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

static inline struct kmem_cache *
cache_from_memcg_idx(struct kmem_cache *s, int idx)
{
        return NULL;
}

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

static inline int memcg_charge_slab(struct kmem_cache *s, gfp_t gfp, int order)
{
        return 0;
}

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

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

        /*
         * 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() &&
            !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
                return s;

        page = virt_to_head_page(x);
        cachep = page->slab_cache;
        if (slab_equal_or_root(cachep, s))
                return cachep;

        pr_err("%s: Wrong slab cache. %s but object is from %s\n",
               __FUNCTION__, s->name, cachep->name);
        WARN_ON_ONCE(1);
        return s;
}
#endif


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

};