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/*

 * Copyright (C) 2006 Ondrej Palkovsky

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** @addtogroup genericmm

 * @{

 */

/** @file

 */

#ifndef KERN_SLAB_H_

#define KERN_SLAB_H_

#include <adt/list.h>

#include <synch/spinlock.h>

#include <atomic.h>

#include <mm/frame.h>

/** Minimum size to be allocated by malloc */

#define SLAB_MIN_MALLOC_W 4

/** Maximum size to be allocated by malloc */

#define SLAB_MAX_MALLOC_W 18

/** Initial Magazine size (TODO: dynamically growing magazines) */

#define SLAB_MAG_SIZE  4

/** If object size is less, store control structure inside SLAB */

#define SLAB_INSIDE_SIZE   (PAGE_SIZE >> 3)

/** Maximum wasted space we allow for cache */

#define SLAB_MAX_BADNESS(cache)   ((PAGE_SIZE << (cache)->order) >> 2)

/* slab_reclaim constants */

#define SLAB_RECLAIM_ALL  0x1 /**< Reclaim all possible memory, because we are in memory stress */

/* cache_create flags */

#define SLAB_CACHE_NOMAGAZINE 0x1 /**< Do not use per-cpu cache */

#define SLAB_CACHE_SLINSIDE   0x2 /**< Have control structure inside SLAB */

#define SLAB_CACHE_MAGDEFERRED (0x4 | SLAB_CACHE_NOMAGAZINE) /**< We add magazine cache later, if we have this flag */

typedef struct {

    link_t link;

    count_t busy;  /**< Count of full slots in magazine */

    count_t size;  /**< Number of slots in magazine */

    void *objs[0]; /**< Slots in magazine */

} slab_magazine_t;

typedef struct {

    slab_magazine_t *current;

    slab_magazine_t *last;

    SPINLOCK_DECLARE(lock);

} slab_mag_cache_t;

typedef struct {

    char *name;

    link_t link;

    /* Configuration */

    size_t size;        /**< Size of slab position - align_up(sizeof(obj)) */

    int (*constructor)(void *obj, int kmflag);

    int (*destructor)(void *obj);

    int flags;      /**< Flags changing behaviour of cache */

    /* Computed values */

    uint8_t order;      /**< Order of frames to be allocated */

    int objects;        /**< Number of objects that fit in */

    /* Statistics */

    atomic_t allocated_slabs;

    atomic_t allocated_objs;

    atomic_t cached_objs;

    atomic_t magazine_counter; /**< How many magazines in magazines list */

    /* Slabs */

    link_t full_slabs;  /**< List of full slabs */

    link_t partial_slabs;   /**< List of partial slabs */

    SPINLOCK_DECLARE(slablock);

    /* Magazines  */

    link_t magazines    /**< List o full magazines */

    SPINLOCK_DECLARE(maglock);

    /** CPU cache */

    slab_mag_cache_t *mag_cache;

} slab_cache_t;

extern slab_cache_t * slab_cache_create(char *name,

                    size_t size,

                    size_t align,

                    int (*constructor)(void *obj, int kmflag),

                    int (*destructor)(void *obj),

                    int flags);

extern void slab_cache_destroy(slab_cache_t *cache);

extern void * slab_alloc(slab_cache_t *cache, int flags);

extern void slab_free(slab_cache_t *cache, void *obj);

extern count_t slab_reclaim(int flags);

/** Initialize slab subsytem */

extern void slab_cache_init(void);

extern void slab_enable_cpucache(void);

/* kconsole debug */

extern void slab_print_list(void);

/* malloc support */

extern void * malloc(unsigned int size, int flags);

extern void free(void *obj);

#endif

/** @}

 */