/* $Id: HGSMIMemAlloc.h 106061 2024-09-16 14:03:52Z vboxsync $ */
/** @file
 * VBox Host Guest Shared Memory Interface (HGSMI) - Memory allocator.
 */

/*
 * Copyright (C) 2014-2024 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * 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, in version 3 of the
 * License.
 *
 * 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, see <https://www.gnu.org/licenses>.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
 * in the VirtualBox 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.
 *
 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
 */

#ifndef VBOX_INCLUDED_Graphics_HGSMIMemAlloc_h
#define VBOX_INCLUDED_Graphics_HGSMIMemAlloc_h
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif

#include "HGSMIDefs.h"
#include "VBoxVideoIPRT.h"


/* Descriptor. */
#define HGSMI_MA_DESC_OFFSET_MASK UINT32_C(0xFFFFFFE0)
#define HGSMI_MA_DESC_FREE_MASK   UINT32_C(0x00000010)
#define HGSMI_MA_DESC_ORDER_MASK  UINT32_C(0x0000000F)

#define HGSMI_MA_DESC_OFFSET(d)  ((d) & HGSMI_MA_DESC_OFFSET_MASK)
#define HGSMI_MA_DESC_IS_FREE(d) (((d) & HGSMI_MA_DESC_FREE_MASK) != 0)
#define HGSMI_MA_DESC_ORDER(d)   ((d) & HGSMI_MA_DESC_ORDER_MASK)

#define HGSMI_MA_DESC_ORDER_BASE UINT32_C(5)

#define HGSMI_MA_BLOCK_SIZE_MIN (UINT32_C(1) << (HGSMI_MA_DESC_ORDER_BASE + 0))
#define HGSMI_MA_BLOCK_SIZE_MAX (UINT32_C(1) << (HGSMI_MA_DESC_ORDER_BASE + HGSMI_MA_DESC_ORDER_MASK))

/* HGSMI_MA_DESC_ORDER_BASE must correspond to HGSMI_MA_DESC_OFFSET_MASK. */
AssertCompile((~HGSMI_MA_DESC_OFFSET_MASK + 1) == HGSMI_MA_BLOCK_SIZE_MIN);


typedef struct HGSMIMABLOCK
{
    RTLISTNODE nodeBlock;
    RTLISTNODE nodeFree;
    HGSMIOFFSET descriptor;
} HGSMIMABLOCK;

typedef struct HGSMIMADATA
{
    HGSMIAREA area;
    HGSMIENV env;
    HGSMISIZE cbMaxBlock;

    uint32_t cBlocks;                                           /* How many blocks in the listBlocks. */
    RTLISTANCHOR listBlocks;                                    /* All memory blocks, sorted. */
    RTLISTANCHOR aListFreeBlocks[HGSMI_MA_DESC_ORDER_MASK + 1]; /* For free blocks of each order. */
} HGSMIMADATA;

RT_C_DECLS_BEGIN

int HGSMIMAInit(HGSMIMADATA *pMA, const HGSMIAREA *pArea,
                HGSMIOFFSET *paDescriptors, uint32_t cDescriptors, HGSMISIZE cbMaxBlock,
                const HGSMIENV *pEnv);
void HGSMIMAUninit(HGSMIMADATA *pMA);

void RT_UNTRUSTED_VOLATILE_HSTGST *HGSMIMAAlloc(HGSMIMADATA *pMA, HGSMISIZE cb);
void HGSMIMAFree(HGSMIMADATA *pMA, void RT_UNTRUSTED_VOLATILE_GUEST *pv);

HGSMIMABLOCK *HGSMIMASearchOffset(HGSMIMADATA *pMA, HGSMIOFFSET off);

uint32_t HGSMIPopCnt32(uint32_t u32);

DECLINLINE(HGSMISIZE) HGSMIMAOrder2Size(HGSMIOFFSET order)
{
    return (UINT32_C(1) << (HGSMI_MA_DESC_ORDER_BASE + order));
}

DECLINLINE(HGSMIOFFSET) HGSMIMASize2Order(HGSMISIZE cb)
{
    HGSMIOFFSET order = HGSMIPopCnt32(cb - 1) - HGSMI_MA_DESC_ORDER_BASE;
#ifdef HGSMI_STRICT
    Assert(HGSMIMAOrder2Size(order) == cb);
#endif
    return order;
}

RT_C_DECLS_END

#endif /* !VBOX_INCLUDED_Graphics_HGSMIMemAlloc_h */