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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 <sound/driver.h> |
23 | #include <linux/init.h> | |
24 | #include <linux/slab.h> | |
25 | #include <sound/core.h> | |
26 | #include <sound/util_mem.h> | |
27 | ||
28 | MODULE_AUTHOR("Takashi Iwai"); | |
29 | MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation"); | |
30 | MODULE_LICENSE("GPL"); | |
31 | ||
03da312a | 32 | #define get_memblk(p) list_entry(p, struct snd_util_memblk, list) |
1da177e4 LT |
33 | |
34 | /* | |
35 | * create a new memory manager | |
36 | */ | |
03da312a | 37 | struct snd_util_memhdr * |
1da177e4 LT |
38 | snd_util_memhdr_new(int memsize) |
39 | { | |
03da312a | 40 | struct snd_util_memhdr *hdr; |
1da177e4 | 41 | |
561b220a | 42 | hdr = kzalloc(sizeof(*hdr), GFP_KERNEL); |
1da177e4 LT |
43 | if (hdr == NULL) |
44 | return NULL; | |
45 | hdr->size = memsize; | |
ef9f0a42 | 46 | mutex_init(&hdr->block_mutex); |
1da177e4 LT |
47 | INIT_LIST_HEAD(&hdr->block); |
48 | ||
49 | return hdr; | |
50 | } | |
51 | ||
52 | /* | |
53 | * free a memory manager | |
54 | */ | |
03da312a | 55 | void snd_util_memhdr_free(struct snd_util_memhdr *hdr) |
1da177e4 LT |
56 | { |
57 | struct list_head *p; | |
58 | ||
59 | snd_assert(hdr != NULL, return); | |
60 | /* release all blocks */ | |
61 | while ((p = hdr->block.next) != &hdr->block) { | |
62 | list_del(p); | |
63 | kfree(get_memblk(p)); | |
64 | } | |
65 | kfree(hdr); | |
66 | } | |
67 | ||
68 | /* | |
69 | * allocate a memory block (without mutex) | |
70 | */ | |
03da312a TI |
71 | struct snd_util_memblk * |
72 | __snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) | |
1da177e4 | 73 | { |
03da312a TI |
74 | struct snd_util_memblk *blk; |
75 | unsigned int units, prev_offset; | |
1da177e4 LT |
76 | struct list_head *p; |
77 | ||
78 | snd_assert(hdr != NULL, return NULL); | |
79 | snd_assert(size > 0, return NULL); | |
80 | ||
81 | /* word alignment */ | |
82 | units = size; | |
83 | if (units & 1) | |
84 | units++; | |
85 | if (units > hdr->size) | |
86 | return NULL; | |
87 | ||
88 | /* look for empty block */ | |
89 | prev_offset = 0; | |
90 | list_for_each(p, &hdr->block) { | |
91 | blk = get_memblk(p); | |
92 | if (blk->offset - prev_offset >= units) | |
93 | goto __found; | |
94 | prev_offset = blk->offset + blk->size; | |
95 | } | |
96 | if (hdr->size - prev_offset < units) | |
97 | return NULL; | |
98 | ||
99 | __found: | |
100 | return __snd_util_memblk_new(hdr, units, p->prev); | |
101 | } | |
102 | ||
103 | ||
104 | /* | |
105 | * create a new memory block with the given size | |
106 | * the block is linked next to prev | |
107 | */ | |
03da312a TI |
108 | struct snd_util_memblk * |
109 | __snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units, | |
1da177e4 LT |
110 | struct list_head *prev) |
111 | { | |
03da312a | 112 | struct snd_util_memblk *blk; |
1da177e4 | 113 | |
03da312a TI |
114 | blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size, |
115 | GFP_KERNEL); | |
1da177e4 LT |
116 | if (blk == NULL) |
117 | return NULL; | |
118 | ||
119 | if (! prev || prev == &hdr->block) | |
120 | blk->offset = 0; | |
121 | else { | |
03da312a | 122 | struct snd_util_memblk *p = get_memblk(prev); |
1da177e4 LT |
123 | blk->offset = p->offset + p->size; |
124 | } | |
125 | blk->size = units; | |
126 | list_add(&blk->list, prev); | |
127 | hdr->nblocks++; | |
128 | hdr->used += units; | |
129 | return blk; | |
130 | } | |
131 | ||
132 | ||
133 | /* | |
134 | * allocate a memory block (with mutex) | |
135 | */ | |
03da312a TI |
136 | struct snd_util_memblk * |
137 | snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) | |
1da177e4 | 138 | { |
03da312a | 139 | struct snd_util_memblk *blk; |
ef9f0a42 | 140 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 141 | blk = __snd_util_mem_alloc(hdr, size); |
ef9f0a42 | 142 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
143 | return blk; |
144 | } | |
145 | ||
146 | ||
147 | /* | |
148 | * remove the block from linked-list and free resource | |
149 | * (without mutex) | |
150 | */ | |
151 | void | |
03da312a | 152 | __snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) |
1da177e4 LT |
153 | { |
154 | list_del(&blk->list); | |
155 | hdr->nblocks--; | |
156 | hdr->used -= blk->size; | |
157 | kfree(blk); | |
158 | } | |
159 | ||
160 | /* | |
161 | * free a memory block (with mutex) | |
162 | */ | |
03da312a | 163 | int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) |
1da177e4 LT |
164 | { |
165 | snd_assert(hdr && blk, return -EINVAL); | |
166 | ||
ef9f0a42 | 167 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 168 | __snd_util_mem_free(hdr, blk); |
ef9f0a42 | 169 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
170 | return 0; |
171 | } | |
172 | ||
173 | /* | |
174 | * return available memory size | |
175 | */ | |
03da312a | 176 | int snd_util_mem_avail(struct snd_util_memhdr *hdr) |
1da177e4 LT |
177 | { |
178 | unsigned int size; | |
ef9f0a42 | 179 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 180 | size = hdr->size - hdr->used; |
ef9f0a42 | 181 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
182 | return size; |
183 | } | |
184 | ||
185 | ||
186 | EXPORT_SYMBOL(snd_util_memhdr_new); | |
187 | EXPORT_SYMBOL(snd_util_memhdr_free); | |
188 | EXPORT_SYMBOL(snd_util_mem_alloc); | |
189 | EXPORT_SYMBOL(snd_util_mem_free); | |
190 | EXPORT_SYMBOL(snd_util_mem_avail); | |
191 | EXPORT_SYMBOL(__snd_util_mem_alloc); | |
192 | EXPORT_SYMBOL(__snd_util_mem_free); | |
193 | EXPORT_SYMBOL(__snd_util_memblk_new); | |
194 | ||
195 | /* | |
196 | * INIT part | |
197 | */ | |
198 | ||
199 | static int __init alsa_util_mem_init(void) | |
200 | { | |
201 | return 0; | |
202 | } | |
203 | ||
204 | static void __exit alsa_util_mem_exit(void) | |
205 | { | |
206 | } | |
207 | ||
208 | module_init(alsa_util_mem_init) | |
209 | module_exit(alsa_util_mem_exit) |