| 1 | /* $Id: bs3-cmn-SlabAllocEx.c 60527 2016-04-18 09:11:04Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * BS3Kit - Bs3SlabAllocEx
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2007-2016 Oracle Corporation
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | * available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | * you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | * General Public License (GPL) as published by the Free Software
|
|---|
| 13 | * Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 14 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 15 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | *
|
|---|
| 17 | * The contents of this file may alternatively be used under the terms
|
|---|
| 18 | * of the Common Development and Distribution License Version 1.0
|
|---|
| 19 | * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
|
|---|
| 20 | * VirtualBox OSE distribution, in which case the provisions of the
|
|---|
| 21 | * CDDL are applicable instead of those of the GPL.
|
|---|
| 22 | *
|
|---|
| 23 | * You may elect to license modified versions of this file under the
|
|---|
| 24 | * terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 25 | */
|
|---|
| 26 |
|
|---|
| 27 | /*********************************************************************************************************************************
|
|---|
| 28 | * Header Files *
|
|---|
| 29 | *********************************************************************************************************************************/
|
|---|
| 30 | #include "bs3kit-template-header.h"
|
|---|
| 31 | #include <iprt/asm.h>
|
|---|
| 32 |
|
|---|
| 33 |
|
|---|
| 34 | #undef Bs3SlabAllocEx
|
|---|
| 35 | BS3_CMN_DEF(void BS3_FAR *, Bs3SlabAllocEx,(PBS3SLABCTL pSlabCtl, uint16_t cChunks, uint16_t fFlags))
|
|---|
| 36 | {
|
|---|
| 37 | BS3_ASSERT(cChunks > 0);
|
|---|
| 38 | if (pSlabCtl->cFreeChunks >= cChunks)
|
|---|
| 39 | {
|
|---|
| 40 | int32_t iBit = ASMBitFirstClear(&pSlabCtl->bmAllocated, pSlabCtl->cChunks);
|
|---|
| 41 | if (iBit >= 0)
|
|---|
| 42 | {
|
|---|
| 43 | BS3_ASSERT(!ASMBitTest(&pSlabCtl->bmAllocated, iBit));
|
|---|
| 44 |
|
|---|
| 45 | while ((uint32_t)iBit + cChunks <= pSlabCtl->cChunks)
|
|---|
| 46 | {
|
|---|
| 47 | /* Check that we've got the requested number of free chunks here. */
|
|---|
| 48 | uint16_t i;
|
|---|
| 49 | for (i = 1; i < cChunks; i++)
|
|---|
| 50 | if (ASMBitTest(&pSlabCtl->bmAllocated, iBit + i))
|
|---|
| 51 | break;
|
|---|
| 52 | if (i == cChunks)
|
|---|
| 53 | {
|
|---|
| 54 | /* Check if the chunks are all in the same tiled segment. */
|
|---|
| 55 | BS3_XPTR_AUTO(void, pvRet);
|
|---|
| 56 | BS3_XPTR_SET_FLAT(void, pvRet,
|
|---|
| 57 | BS3_XPTR_GET_FLAT(uint8_t, pSlabCtl->pbStart) + ((uint32_t)iBit << pSlabCtl->cChunkShift));
|
|---|
| 58 | if ( !(fFlags & BS3_SLAB_ALLOC_F_SAME_TILE)
|
|---|
| 59 | || (BS3_XPTR_GET_FLAT(void, pvRet) >> 16)
|
|---|
| 60 | == ((BS3_XPTR_GET_FLAT(void, pvRet) + ((uint32_t)cChunks << pSlabCtl->cChunkShift) - 1) >> 16) )
|
|---|
| 61 | {
|
|---|
| 62 | /* Complete the allocation. */
|
|---|
| 63 | void *fpRet;
|
|---|
| 64 | for (i = 0; i < cChunks; i++)
|
|---|
| 65 | ASMBitSet(&pSlabCtl->bmAllocated, iBit + i);
|
|---|
| 66 | pSlabCtl->cFreeChunks -= cChunks;
|
|---|
| 67 | fpRet = BS3_XPTR_GET(void, pvRet);
|
|---|
| 68 | #if ARCH_BITS == 16
|
|---|
| 69 | BS3_ASSERT(fpRet != NULL);
|
|---|
| 70 | #endif
|
|---|
| 71 | return fpRet;
|
|---|
| 72 | }
|
|---|
| 73 |
|
|---|
| 74 | /*
|
|---|
| 75 | * We're crossing a tiled segment boundrary.
|
|---|
| 76 | * Skip to the start of the next segment and retry there.
|
|---|
| 77 | * (We already know that the first chunk in the next tiled
|
|---|
| 78 | * segment is free, otherwise we wouldn't have a crossing.)
|
|---|
| 79 | */
|
|---|
| 80 | BS3_ASSERT(((uint32_t)cChunks << pSlabCtl->cChunkShift) <= _64K);
|
|---|
| 81 | i = BS3_XPTR_GET_FLAT_LOW(void, pvRet);
|
|---|
| 82 | i = UINT16_C(0) - i;
|
|---|
| 83 | i >>= pSlabCtl->cChunkShift;
|
|---|
| 84 | iBit += i;
|
|---|
| 85 | }
|
|---|
| 86 | else
|
|---|
| 87 | {
|
|---|
| 88 | /*
|
|---|
| 89 | * Continue searching.
|
|---|
| 90 | */
|
|---|
| 91 | iBit = ASMBitNextClear(&pSlabCtl->bmAllocated, pSlabCtl->cChunks, iBit + i);
|
|---|
| 92 | if (iBit < 0)
|
|---|
| 93 | break;
|
|---|
| 94 | }
|
|---|
| 95 | }
|
|---|
| 96 | }
|
|---|
| 97 | }
|
|---|
| 98 | return NULL;
|
|---|
| 99 | }
|
|---|
| 100 |
|
|---|
