source: cmedia/trunk/Sblive/emuadxmg.c@ 354

Last change on this file since 354 was 354, checked in by stevenhl, 17 years ago

Import untested baseline cmedia sources, work products and binaries
Binaries and work products should be deleted from repository.
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1/* $Id: emuadxmg.c,v 1.1 2000/04/23 14:55:43 ktk Exp $ */
2
3
4/*
5 **********************************************************************
6 * emuadxmg.c - Address space manager for emu10k1 driver
7 * Copyright 1999, 2000 Creative Labs, Inc.
8 *
9 **********************************************************************
10 *
11 * Date Author Summary of changes
12 * ---- ------ ------------------
13 * October 20, 1999 Bertrand Lee base code release
14 *
15 **********************************************************************
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public
28 * License along with this program; if not, write to the Free
29 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
30 * USA.
31 *
32 **********************************************************************
33 */
34
35#include "hwaccess.h"
36
37/* Allocates emu address space */
38
39int emu10k1_addxmgr_alloc(u32 size, struct emu10k1_card *card)
40{
41 u16 *pagetable = card->emupagetable;
42 u16 index = 0;
43 u16 numpages;
44 unsigned long flags;
45
46 /* Convert bytes to pages */
47 numpages = (size / EMUPAGESIZE) + ((size % EMUPAGESIZE) ? 1 : 0);
48
49 while (index < (MAXPAGES - RESERVED - 1)) {
50 if (pagetable[index] & 0x8000) {
51 /* This block of pages is in use, jump to the start of the next block. */
52 index += (pagetable[index] & 0x7fff);
53 } else {
54 /* Found free block */
55 if (pagetable[index] >= numpages) {
56 spin_lock_irqsave(&card->lock, flags);
57
58 /* Block is large enough */
59
60 /* If free block is larger than the block requested
61 * then adjust the size of the block remaining */
62 if (pagetable[index] > numpages)
63 pagetable[index + numpages] = pagetable[index] - numpages;
64
65 pagetable[index] = (numpages | 0x8000); /* Mark block as used */
66
67 spin_unlock_irqrestore(&card->lock, flags);
68
69 return index;
70 } else {
71 /* Block too small, jump to the start of the next block */
72 index += pagetable[index];
73 }
74 }
75 }
76
77 return -1;
78}
79
80/* Frees a previously allocated emu address space. */
81
82void emu10k1_addxmgr_free(struct emu10k1_card *card, int index)
83{
84 u16 *pagetable = card->emupagetable;
85 u16 origsize = 0;
86 unsigned long flags;
87
88 spin_lock_irqsave(&card->lock, flags);
89
90 if (pagetable[index] & 0x8000) {
91 /* Block is allocated - mark block as free */
92 origsize = pagetable[index] & 0x7fff;
93 pagetable[index] = origsize;
94
95 /* If next block is free, we concat both blocks */
96 if (!(pagetable[index + origsize] & 0x8000))
97 pagetable[index] += pagetable[index + origsize] & 0x7fff;
98 }
99
100 spin_unlock_irqrestore(&card->lock, flags);
101
102 return;
103}
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