1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/* $Id: bs3-cmn-SlabAllocEx.c $ */
/** @file
* BS3Kit - Bs3SlabAllocEx
*/
/*
* Copyright (C) 2007-2023 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
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#include "bs3kit-template-header.h"
#include <iprt/asm.h>
#undef Bs3SlabAllocEx
BS3_CMN_DEF(void BS3_FAR *, Bs3SlabAllocEx,(PBS3SLABCTL pSlabCtl, uint16_t cChunks, uint16_t fFlags))
{
BS3_ASSERT(cChunks > 0);
if (pSlabCtl->cFreeChunks >= cChunks)
{
int32_t iBit = ASMBitFirstClear(&pSlabCtl->bmAllocated, pSlabCtl->cChunks);
if (iBit >= 0)
{
BS3_ASSERT(!ASMBitTest(&pSlabCtl->bmAllocated, iBit));
while ((uint32_t)iBit + cChunks <= pSlabCtl->cChunks)
{
/* Check that we've got the requested number of free chunks here. */
uint16_t i;
for (i = 1; i < cChunks; i++)
if (ASMBitTest(&pSlabCtl->bmAllocated, iBit + i))
break;
if (i == cChunks)
{
/* Check if the chunks are all in the same tiled segment. */
BS3_XPTR_AUTO(void, pvRet);
BS3_XPTR_SET_FLAT(void, pvRet,
BS3_XPTR_GET_FLAT(uint8_t, pSlabCtl->pbStart) + ((uint32_t)iBit << pSlabCtl->cChunkShift));
if ( !(fFlags & BS3_SLAB_ALLOC_F_SAME_TILE)
|| (BS3_XPTR_GET_FLAT(void, pvRet) >> 16)
== ((BS3_XPTR_GET_FLAT(void, pvRet) + ((uint32_t)cChunks << pSlabCtl->cChunkShift) - 1) >> 16) )
{
/* Complete the allocation. */
void *fpRet;
for (i = 0; i < cChunks; i++)
ASMBitSet(&pSlabCtl->bmAllocated, iBit + i);
pSlabCtl->cFreeChunks -= cChunks;
fpRet = BS3_XPTR_GET(void, pvRet);
#if ARCH_BITS == 16
BS3_ASSERT(fpRet != NULL);
#endif
return fpRet;
}
/*
* We're crossing a tiled segment boundrary.
* Skip to the start of the next segment and retry there.
* (We already know that the first chunk in the next tiled
* segment is free, otherwise we wouldn't have a crossing.)
*/
BS3_ASSERT(((uint32_t)cChunks << pSlabCtl->cChunkShift) <= _64K);
i = BS3_XPTR_GET_FLAT_LOW(void, pvRet);
i = UINT16_C(0) - i;
i >>= pSlabCtl->cChunkShift;
iBit += i;
}
else
{
/*
* Continue searching.
*/
iBit = ASMBitNextClear(&pSlabCtl->bmAllocated, pSlabCtl->cChunks, iBit + i);
if (iBit < 0)
break;
}
}
}
}
return NULL;
}
|
