#ifndef _LINUX_SLUB_DEF_H
#define _LINUX_SLUB_DEF_H

/*
 * SLUB : A Slab allocator without object queues.
 *
 * (C) 2007 SGI, Christoph Lameter
 */
#include <linux/types.h>
#include <linux/gfp.h>
#include <linux/bug.h>
#include <linux/workqueue.h>
#include <linux/kobject.h>

#include <linux/kmemleak.h>

enum stat_item {
        ALLOC_FASTPATH,         /* Allocation from cpu slab */
        ALLOC_SLOWPATH,         /* Allocation by getting a new cpu slab */
        FREE_FASTPATH,          /* Free to cpu slub */
        FREE_SLOWPATH,          /* Freeing not to cpu slab */
        FREE_FROZEN,            /* Freeing to frozen slab */
        FREE_ADD_PARTIAL,       /* Freeing moves slab to partial list */
        FREE_REMOVE_PARTIAL,    /* Freeing removes last object */
        ALLOC_FROM_PARTIAL,     /* Cpu slab acquired from node partial list */
        ALLOC_SLAB,             /* Cpu slab acquired from page allocator */
        ALLOC_REFILL,           /* Refill cpu slab from slab freelist */
        ALLOC_NODE_MISMATCH,    /* Switching cpu slab */
        FREE_SLAB,              /* Slab freed to the page allocator */
        CPUSLAB_FLUSH,          /* Abandoning of the cpu slab */
        DEACTIVATE_FULL,        /* Cpu slab was full when deactivated */
        DEACTIVATE_EMPTY,       /* Cpu slab was empty when deactivated */
        DEACTIVATE_TO_HEAD,     /* Cpu slab was moved to the head of partials */
        DEACTIVATE_TO_TAIL,     /* Cpu slab was moved to the tail of partials */
        DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
        DEACTIVATE_BYPASS,      /* Implicit deactivation */
        ORDER_FALLBACK,         /* Number of times fallback was necessary */
        CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
        CMPXCHG_DOUBLE_FAIL,    /* Number of times that cmpxchg double did not match */
        CPU_PARTIAL_ALLOC,      /* Used cpu partial on alloc */
        CPU_PARTIAL_FREE,       /* Refill cpu partial on free */
        CPU_PARTIAL_NODE,       /* Refill cpu partial from node partial */
        CPU_PARTIAL_DRAIN,      /* Drain cpu partial to node partial */
        NR_SLUB_STAT_ITEMS };

struct kmem_cache_cpu {
        void **freelist;        /* Pointer to next available object */
        unsigned long tid;      /* Globally unique transaction id */
        struct page *page;      /* The slab from which we are allocating */
        struct page *partial;   /* Partially allocated frozen slabs */
        int node;               /* The node of the page (or -1 for debug) */
#ifdef CONFIG_SLUB_STATS
        unsigned stat[NR_SLUB_STAT_ITEMS];
#endif
};

struct kmem_cache_node {
        spinlock_t list_lock;   /* Protect partial list and nr_partial */
        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
};

/*
 * Word size structure that can be atomically updated or read and that
 * contains both the order and the number of objects that a slab of the
 * given order would contain.
 */
struct kmem_cache_order_objects {
        unsigned long x;
};

/*
 * Slab cache management.
 */
struct kmem_cache {
        struct kmem_cache_cpu __percpu *cpu_slab;
        /* Used for retriving partial slabs etc */
        unsigned long flags;
        unsigned long min_partial;
        int size;               /* The size of an object including meta data */
        int objsize;            /* The size of an object without meta data */
        int offset;             /* Free pointer offset. */
        int cpu_partial;        /* Number of per cpu partial objects to keep around */
        struct kmem_cache_order_objects oo;

        /* Allocation and freeing of slabs */
        struct kmem_cache_order_objects max;
        struct kmem_cache_order_objects min;
        gfp_t allocflags;       /* gfp flags to use on each alloc */
        int refcount;           /* Refcount for slab cache destroy */
        void (*ctor)(void *);
        int inuse;              /* Offset to metadata */
        int align;              /* Alignment */
        int reserved;           /* Reserved bytes at the end of slabs */
        const char *name;       /* Name (only for display!) */
        struct list_head list;  /* List of slab caches */
#ifdef CONFIG_SYSFS
        struct kobject kobj;    /* For sysfs */
#endif

#ifdef CONFIG_NUMA
        /*
         * Defragmentation by allocating from a remote node.
         */
        int remote_node_defrag_ratio;
#endif
        struct kmem_cache_node *node[MAX_NUMNODES];
};

/*
 * Kmalloc subsystem.
 */
#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
#else
#define KMALLOC_MIN_SIZE 8
#endif

#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)

/*
 * Maximum kmalloc object size handled by SLUB. Larger object allocations
 * are passed through to the page allocator. The page allocator "fastpath"
 * is relatively slow so we need this value sufficiently high so that
 * performance critical objects are allocated through the SLUB fastpath.
 *
 * This should be dropped to PAGE_SIZE / 2 once the page allocator
 * "fastpath" becomes competitive with the slab allocator fastpaths.
 */
#define SLUB_MAX_SIZE (2 * PAGE_SIZE)

#define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)

#ifdef CONFIG_ZONE_DMA
#define SLUB_DMA __GFP_DMA
#else
/* Disable DMA functionality */
#define SLUB_DMA (__force gfp_t)0
#endif

/*
 * We keep the general caches in an array of slab caches that are used for
 * 2^x bytes of allocations.
 */
extern struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];

/*
 * Sorry that the following has to be that ugly but some versions of GCC
 * have trouble with constant propagation and loops.
 */
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;
/*
 * The following is only needed to support architectures with a larger page
 * size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
 * size we would have to go up to 128k.
 */
        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;
        BUG();
        return -1; /* Will never be reached */

/*
 * What we really wanted to do and cannot do because of compiler issues is:
 *      int i;
 *      for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
 *              if (size <= (1 << i))
 *                      return i;
 */
}

/*
 * Find the slab cache for a given combination of allocation flags and size.
 *
 * This ought to end up with a global pointer to the right cache
 * in kmalloc_caches.
 */
static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
{
        int index = kmalloc_index(size);

        if (index == 0)
                return NULL;

        return kmalloc_caches[index];
}

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

static __always_inline void *
kmalloc_order(size_t size, gfp_t flags, unsigned int order)
{
        void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
        kmemleak_alloc(ret, size, 1, flags);
        return ret;
}

/**
 * Calling this on allocated memory will check that the memory
 * is expected to be in use, and print warnings if not.
 */
#ifdef CONFIG_SLUB_DEBUG
extern bool verify_mem_not_deleted(const void *x);
#else
static inline bool verify_mem_not_deleted(const void *x)
{
        return true;
}
#endif

#ifdef CONFIG_TRACING
extern void *
kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size);
extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
#else
static __always_inline void *
kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
{
        return kmem_cache_alloc(s, gfpflags);
}

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);
}

static __always_inline void *kmalloc(size_t size, gfp_t flags)
{
        if (__builtin_constant_p(size)) {
                if (size > SLUB_MAX_SIZE)
                        return kmalloc_large(size, flags);

                if (!(flags & SLUB_DMA)) {
                        struct kmem_cache *s = kmalloc_slab(size);

                        if (!s)
                                return ZERO_SIZE_PTR;

                        return kmem_cache_alloc_trace(s, flags, size);
                }
        }
        return __kmalloc(size, flags);
}

#ifdef CONFIG_NUMA
void *__kmalloc_node(size_t size, gfp_t flags, int node);
void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);

#ifdef CONFIG_TRACING
extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
                                           gfp_t gfpflags,
                                           int node, size_t size);
#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_node(s, gfpflags, node);
}
#endif

static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
{
        if (__builtin_constant_p(size) &&
                size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
                        struct kmem_cache *s = kmalloc_slab(size);

                if (!s)
                        return ZERO_SIZE_PTR;

                return kmem_cache_alloc_node_trace(s, flags, node, size);
        }
        return __kmalloc_node(size, flags, node);
}
#endif

#endif /* _LINUX_SLUB_DEF_H */