/*
 * Copyright (c) 2011 Free Software Foundation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/*
 * Copyright (c) 2010, 2011 Richard Braun.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * 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.
 *
 *
 * Object caching memory allocator.
 */

#ifndef _KERN_SLAB_H
#define _KERN_SLAB_H

#include <cache.h>
#include <mach/machine/vm_types.h>
#include <sys/types.h>
#include <vm/vm_types.h>

/*
 * Object cache.
 */
struct kmem_cache;

/*
 * Type for constructor functions.
 *
 * The pre-constructed state of an object is supposed to include only
 * elements such as e.g. linked lists, locks, reference counters. Therefore
 * constructors are expected to 1) never fail and 2) not need any
 * user-provided data. The first constraint implies that object construction
 * never performs dynamic resource allocation, which also means there is no
 * need for destructors.
 */
typedef void (*kmem_cache_ctor_t)(void *obj);

/*
 * Types for slab allocation/free functions.
 *
 * All addresses and sizes must be page-aligned.
 */
typedef vm_offset_t (*kmem_slab_alloc_fn_t)(vm_size_t);
typedef void (*kmem_slab_free_fn_t)(vm_offset_t, vm_size_t);

#include <kern/slab_i.h>

/*
 * Mach-style declarations for struct kmem_cache.
 */
typedef struct kmem_cache *kmem_cache_t;
#define KMEM_CACHE_NULL ((kmem_cache_t) 0)

/*
 * VM submap for slab allocations.
 */
extern vm_map_t kmem_map;

/*
 * Cache initialization flags.
 */
#define KMEM_CACHE_NOCPUPOOL    0x1 /* Don't use the per-cpu pools */
#define KMEM_CACHE_NOOFFSLAB    0x2 /* Don't allocate external slab data */
#define KMEM_CACHE_VERIFY       0x4 /* Use debugging facilities */

/*
 * Initialize a cache.
 *
 * If a slab allocation/free function pointer is NULL, the default backend
 * (vm_kmem on the kernel map) is used for the allocation/free action.
 */
void kmem_cache_init(struct kmem_cache *cache, const char *name,
                     size_t obj_size, size_t align, kmem_cache_ctor_t ctor,
                     kmem_slab_alloc_fn_t slab_alloc_fn,
                     kmem_slab_free_fn_t slab_free_fn, int flags);

/*
 * Allocate an object from a cache.
 */
vm_offset_t kmem_cache_alloc(struct kmem_cache *cache);

/*
 * Release an object to its cache.
 */
void kmem_cache_free(struct kmem_cache *cache, vm_offset_t obj);

/*
 * Initialize the memory allocator module.
 */
void slab_bootstrap(void);
void slab_init(void);

/*
 * Release free slabs to the VM system.
 */
void slab_collect(void);

/*
 * Display a summary of all kernel caches.
 */
void slab_info(void);

#endif /* _KERN_SLAB_H */