/* $Id: bs3-cmn-MemAlloc.c 58814 2015-11-22 06:50:50Z vboxsync $ */
/** @file
 * BS3Kit - Bs3MemAlloc
 */

/*
 * Copyright (C) 2007-2015 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
 * VirtualBox OSE distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 */

/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#include "bs3kit-template-header.h"
#include "bs3-cmn-memory.h"
#include <iprt/asm.h>


BS3_DECL(void BS3_FAR *) Bs3MemAlloc(BS3MEMKIND enmKind, size_t cb)
{
    void BS3_FAR   *pvRet;
    uint8_t         idxSlabList = bs3MemSizeToSlabListIndex(cb);
    if (idxSlabList < BS3_MEM_SLAB_LIST_COUNT)
    {
        /*
         * Try allocate a chunk from the list.
         */
        PBS3SLABHEAD pHead = enmKind == BS3MEMKIND_REAL
                           ? &BS3_MSC64_FIXUP_HACK(BS3SLABHEAD, BS3_DATA_NM(g_aBs3LowSlabLists))[idxSlabList]
                           : &BS3_MSC64_FIXUP_HACK(BS3SLABHEAD, BS3_DATA_NM(g_aBs3UpperTiledSlabLists))[idxSlabList];

        BS3_ASSERT(BS3_MSC64_FIXUP_HACK(BS3SLABHEAD, BS3_DATA_NM(g_aBs3LowSlabLists))[idxSlabList].cbChunk >= cb);
        pvRet = Bs3SlabListAlloc(pHead);
        if (pvRet)
        { /* likely */ }
        else
        {
            /*
             * Grow the list.
             */
            PBS3SLABCTL pNew = (PBS3SLABCTL)Bs3SlabAlloc(  enmKind == BS3MEMKIND_REAL
                                                         ? &BS3_DATA_NM(g_Bs3Mem4KLow).Core
                                                         : &BS3_DATA_NM(g_Bs3Mem4KUpperTiled).Core);
            BS3_ASSERT(((uintptr_t)pNew & 0xfff) == 0);
            if (pNew)
            {
                uint16_t const      cbHdr = BS3_DATA_NM(g_cbBs3SlabCtlSizesforLists)[idxSlabList];
                BS3_XPTR_AUTO(void, pvNew);
                BS3_XPTR_SET(void, pvNew, pNew);

                Bs3SlabInit(pNew, cbHdr, BS3_XPTR_GET_FLAT(void, pvNew) + cbHdr, _4K - cbHdr, pHead->cbChunk);
                Bs3SlabListAdd(pHead, pNew);

                pvRet = Bs3SlabListAlloc(pHead);
            }
        }
    }
    else
    {
        /*
         * Allocate one or more pages.
         */
        size_t   const cbAligned = RT_ALIGN_Z(cb, _4K);
        uint16_t const cPages    = cbAligned >> 12 /* div _4K */;

        pvRet = Bs3SlabAllocEx(enmKind == BS3MEMKIND_REAL
                               ? &BS3_DATA_NM(g_Bs3Mem4KLow).Core : &BS3_DATA_NM(g_Bs3Mem4KUpperTiled).Core,
                               cPages,
                               cPages <= _64K / _4K ? BS3_SLAB_ALLOC_F_SAME_TILE : 0);
    }
    return pvRet;
}