diff options
Diffstat (limited to 'sound/oss/emu10k1/emuadxmg.c')
-rw-r--r-- | sound/oss/emu10k1/emuadxmg.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/sound/oss/emu10k1/emuadxmg.c b/sound/oss/emu10k1/emuadxmg.c new file mode 100644 index 000000000000..d7d2d4caf7ba --- /dev/null +++ b/sound/oss/emu10k1/emuadxmg.c | |||
@@ -0,0 +1,104 @@ | |||
1 | |||
2 | /* | ||
3 | ********************************************************************** | ||
4 | * emuadxmg.c - Address space manager for emu10k1 driver | ||
5 | * Copyright 1999, 2000 Creative Labs, Inc. | ||
6 | * | ||
7 | ********************************************************************** | ||
8 | * | ||
9 | * Date Author Summary of changes | ||
10 | * ---- ------ ------------------ | ||
11 | * October 20, 1999 Bertrand Lee base code release | ||
12 | * | ||
13 | ********************************************************************** | ||
14 | * | ||
15 | * This program is free software; you can redistribute it and/or | ||
16 | * modify it under the terms of the GNU General Public License as | ||
17 | * published by the Free Software Foundation; either version 2 of | ||
18 | * the License, or (at your option) any later version. | ||
19 | * | ||
20 | * This program is distributed in the hope that it will be useful, | ||
21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
23 | * GNU General Public License for more details. | ||
24 | * | ||
25 | * You should have received a copy of the GNU General Public | ||
26 | * License along with this program; if not, write to the Free | ||
27 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, | ||
28 | * USA. | ||
29 | * | ||
30 | ********************************************************************** | ||
31 | */ | ||
32 | |||
33 | #include "hwaccess.h" | ||
34 | |||
35 | /* Allocates emu address space */ | ||
36 | |||
37 | int emu10k1_addxmgr_alloc(u32 size, struct emu10k1_card *card) | ||
38 | { | ||
39 | u16 *pagetable = card->emupagetable; | ||
40 | u16 index = 0; | ||
41 | u16 numpages; | ||
42 | unsigned long flags; | ||
43 | |||
44 | /* Convert bytes to pages */ | ||
45 | numpages = (size / EMUPAGESIZE) + ((size % EMUPAGESIZE) ? 1 : 0); | ||
46 | |||
47 | spin_lock_irqsave(&card->lock, flags); | ||
48 | |||
49 | while (index < (MAXPAGES - 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 | |||
57 | /* Block is large enough */ | ||
58 | |||
59 | /* If free block is larger than the block requested | ||
60 | * then adjust the size of the block remaining */ | ||
61 | if (pagetable[index] > numpages) | ||
62 | pagetable[index + numpages] = pagetable[index] - numpages; | ||
63 | |||
64 | pagetable[index] = (numpages | 0x8000); /* Mark block as used */ | ||
65 | |||
66 | spin_unlock_irqrestore(&card->lock, flags); | ||
67 | |||
68 | return index; | ||
69 | } else { | ||
70 | /* Block too small, jump to the start of the next block */ | ||
71 | index += pagetable[index]; | ||
72 | } | ||
73 | } | ||
74 | } | ||
75 | |||
76 | spin_unlock_irqrestore(&card->lock, flags); | ||
77 | |||
78 | return -1; | ||
79 | } | ||
80 | |||
81 | /* Frees a previously allocated emu address space. */ | ||
82 | |||
83 | void emu10k1_addxmgr_free(struct emu10k1_card *card, int index) | ||
84 | { | ||
85 | u16 *pagetable = card->emupagetable; | ||
86 | u16 origsize = 0; | ||
87 | unsigned long flags; | ||
88 | |||
89 | spin_lock_irqsave(&card->lock, flags); | ||
90 | |||
91 | if (pagetable[index] & 0x8000) { | ||
92 | /* Block is allocated - mark block as free */ | ||
93 | origsize = pagetable[index] & 0x7fff; | ||
94 | pagetable[index] = origsize; | ||
95 | |||
96 | /* If next block is free, we concat both blocks */ | ||
97 | if (!(pagetable[index + origsize] & 0x8000)) | ||
98 | pagetable[index] += pagetable[index + origsize] & 0x7fff; | ||
99 | } | ||
100 | |||
101 | spin_unlock_irqrestore(&card->lock, flags); | ||
102 | |||
103 | return; | ||
104 | } | ||