Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2000 Takashi Iwai <tiwai@suse.de> | |
3 | * | |
4 | * Generic memory management routines for soundcard memory allocation | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
19 | */ | |
20 | ||
ef9f0a42 | 21 | #include <linux/mutex.h> |
1da177e4 LT |
22 | #include <linux/init.h> |
23 | #include <linux/slab.h> | |
24 | #include <sound/core.h> | |
25 | #include <sound/util_mem.h> | |
26 | ||
27 | MODULE_AUTHOR("Takashi Iwai"); | |
28 | MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation"); | |
29 | MODULE_LICENSE("GPL"); | |
30 | ||
03da312a | 31 | #define get_memblk(p) list_entry(p, struct snd_util_memblk, list) |
1da177e4 LT |
32 | |
33 | /* | |
34 | * create a new memory manager | |
35 | */ | |
03da312a | 36 | struct snd_util_memhdr * |
1da177e4 LT |
37 | snd_util_memhdr_new(int memsize) |
38 | { | |
03da312a | 39 | struct snd_util_memhdr *hdr; |
1da177e4 | 40 | |
561b220a | 41 | hdr = kzalloc(sizeof(*hdr), GFP_KERNEL); |
1da177e4 LT |
42 | if (hdr == NULL) |
43 | return NULL; | |
44 | hdr->size = memsize; | |
ef9f0a42 | 45 | mutex_init(&hdr->block_mutex); |
1da177e4 LT |
46 | INIT_LIST_HEAD(&hdr->block); |
47 | ||
48 | return hdr; | |
49 | } | |
50 | ||
51 | /* | |
52 | * free a memory manager | |
53 | */ | |
03da312a | 54 | void snd_util_memhdr_free(struct snd_util_memhdr *hdr) |
1da177e4 LT |
55 | { |
56 | struct list_head *p; | |
57 | ||
58 | snd_assert(hdr != NULL, return); | |
59 | /* release all blocks */ | |
60 | while ((p = hdr->block.next) != &hdr->block) { | |
61 | list_del(p); | |
62 | kfree(get_memblk(p)); | |
63 | } | |
64 | kfree(hdr); | |
65 | } | |
66 | ||
67 | /* | |
68 | * allocate a memory block (without mutex) | |
69 | */ | |
03da312a TI |
70 | struct snd_util_memblk * |
71 | __snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) | |
1da177e4 | 72 | { |
03da312a TI |
73 | struct snd_util_memblk *blk; |
74 | unsigned int units, prev_offset; | |
1da177e4 LT |
75 | struct list_head *p; |
76 | ||
77 | snd_assert(hdr != NULL, return NULL); | |
78 | snd_assert(size > 0, return NULL); | |
79 | ||
80 | /* word alignment */ | |
81 | units = size; | |
82 | if (units & 1) | |
83 | units++; | |
84 | if (units > hdr->size) | |
85 | return NULL; | |
86 | ||
87 | /* look for empty block */ | |
88 | prev_offset = 0; | |
89 | list_for_each(p, &hdr->block) { | |
90 | blk = get_memblk(p); | |
91 | if (blk->offset - prev_offset >= units) | |
92 | goto __found; | |
93 | prev_offset = blk->offset + blk->size; | |
94 | } | |
95 | if (hdr->size - prev_offset < units) | |
96 | return NULL; | |
97 | ||
98 | __found: | |
99 | return __snd_util_memblk_new(hdr, units, p->prev); | |
100 | } | |
101 | ||
102 | ||
103 | /* | |
104 | * create a new memory block with the given size | |
105 | * the block is linked next to prev | |
106 | */ | |
03da312a TI |
107 | struct snd_util_memblk * |
108 | __snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units, | |
1da177e4 LT |
109 | struct list_head *prev) |
110 | { | |
03da312a | 111 | struct snd_util_memblk *blk; |
1da177e4 | 112 | |
03da312a TI |
113 | blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size, |
114 | GFP_KERNEL); | |
1da177e4 LT |
115 | if (blk == NULL) |
116 | return NULL; | |
117 | ||
8e6c962c | 118 | if (prev == &hdr->block) |
1da177e4 LT |
119 | blk->offset = 0; |
120 | else { | |
03da312a | 121 | struct snd_util_memblk *p = get_memblk(prev); |
1da177e4 LT |
122 | blk->offset = p->offset + p->size; |
123 | } | |
124 | blk->size = units; | |
125 | list_add(&blk->list, prev); | |
126 | hdr->nblocks++; | |
127 | hdr->used += units; | |
128 | return blk; | |
129 | } | |
130 | ||
131 | ||
132 | /* | |
133 | * allocate a memory block (with mutex) | |
134 | */ | |
03da312a TI |
135 | struct snd_util_memblk * |
136 | snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) | |
1da177e4 | 137 | { |
03da312a | 138 | struct snd_util_memblk *blk; |
ef9f0a42 | 139 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 140 | blk = __snd_util_mem_alloc(hdr, size); |
ef9f0a42 | 141 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
142 | return blk; |
143 | } | |
144 | ||
145 | ||
146 | /* | |
147 | * remove the block from linked-list and free resource | |
148 | * (without mutex) | |
149 | */ | |
150 | void | |
03da312a | 151 | __snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) |
1da177e4 LT |
152 | { |
153 | list_del(&blk->list); | |
154 | hdr->nblocks--; | |
155 | hdr->used -= blk->size; | |
156 | kfree(blk); | |
157 | } | |
158 | ||
159 | /* | |
160 | * free a memory block (with mutex) | |
161 | */ | |
03da312a | 162 | int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) |
1da177e4 LT |
163 | { |
164 | snd_assert(hdr && blk, return -EINVAL); | |
165 | ||
ef9f0a42 | 166 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 167 | __snd_util_mem_free(hdr, blk); |
ef9f0a42 | 168 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
169 | return 0; |
170 | } | |
171 | ||
172 | /* | |
173 | * return available memory size | |
174 | */ | |
03da312a | 175 | int snd_util_mem_avail(struct snd_util_memhdr *hdr) |
1da177e4 LT |
176 | { |
177 | unsigned int size; | |
ef9f0a42 | 178 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 179 | size = hdr->size - hdr->used; |
ef9f0a42 | 180 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
181 | return size; |
182 | } | |
183 | ||
184 | ||
185 | EXPORT_SYMBOL(snd_util_memhdr_new); | |
186 | EXPORT_SYMBOL(snd_util_memhdr_free); | |
187 | EXPORT_SYMBOL(snd_util_mem_alloc); | |
188 | EXPORT_SYMBOL(snd_util_mem_free); | |
189 | EXPORT_SYMBOL(snd_util_mem_avail); | |
190 | EXPORT_SYMBOL(__snd_util_mem_alloc); | |
191 | EXPORT_SYMBOL(__snd_util_mem_free); | |
192 | EXPORT_SYMBOL(__snd_util_memblk_new); | |
193 | ||
194 | /* | |
195 | * INIT part | |
196 | */ | |
197 | ||
198 | static int __init alsa_util_mem_init(void) | |
199 | { | |
200 | return 0; | |
201 | } | |
202 | ||
203 | static void __exit alsa_util_mem_exit(void) | |
204 | { | |
205 | } | |
206 | ||
207 | module_init(alsa_util_mem_init) | |
208 | module_exit(alsa_util_mem_exit) |