ia64/linux-2.6.18-xen.hg

view sound/synth/util_mem.c @ 782:9ab1c319531f

merge with linux-2.6.18-xen.hg
author Isaku Yamahata <yamahata@valinux.co.jp>
date Wed Jan 28 13:07:23 2009 +0900 (2009-01-28)
parents 831230e53067
children
line source
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 */
21 #include <linux/mutex.h>
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>
28 MODULE_AUTHOR("Takashi Iwai");
29 MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation");
30 MODULE_LICENSE("GPL");
32 #define get_memblk(p) list_entry(p, struct snd_util_memblk, list)
34 /*
35 * create a new memory manager
36 */
37 struct snd_util_memhdr *
38 snd_util_memhdr_new(int memsize)
39 {
40 struct snd_util_memhdr *hdr;
42 hdr = kzalloc(sizeof(*hdr), GFP_KERNEL);
43 if (hdr == NULL)
44 return NULL;
45 hdr->size = memsize;
46 mutex_init(&hdr->block_mutex);
47 INIT_LIST_HEAD(&hdr->block);
49 return hdr;
50 }
52 /*
53 * free a memory manager
54 */
55 void snd_util_memhdr_free(struct snd_util_memhdr *hdr)
56 {
57 struct list_head *p;
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 }
68 /*
69 * allocate a memory block (without mutex)
70 */
71 struct snd_util_memblk *
72 __snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size)
73 {
74 struct snd_util_memblk *blk;
75 unsigned int units, prev_offset;
76 struct list_head *p;
78 snd_assert(hdr != NULL, return NULL);
79 snd_assert(size > 0, return NULL);
81 /* word alignment */
82 units = size;
83 if (units & 1)
84 units++;
85 if (units > hdr->size)
86 return NULL;
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;
99 __found:
100 return __snd_util_memblk_new(hdr, units, p->prev);
101 }
104 /*
105 * create a new memory block with the given size
106 * the block is linked next to prev
107 */
108 struct snd_util_memblk *
109 __snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units,
110 struct list_head *prev)
111 {
112 struct snd_util_memblk *blk;
114 blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size,
115 GFP_KERNEL);
116 if (blk == NULL)
117 return NULL;
119 if (! prev || prev == &hdr->block)
120 blk->offset = 0;
121 else {
122 struct snd_util_memblk *p = get_memblk(prev);
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 }
133 /*
134 * allocate a memory block (with mutex)
135 */
136 struct snd_util_memblk *
137 snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size)
138 {
139 struct snd_util_memblk *blk;
140 mutex_lock(&hdr->block_mutex);
141 blk = __snd_util_mem_alloc(hdr, size);
142 mutex_unlock(&hdr->block_mutex);
143 return blk;
144 }
147 /*
148 * remove the block from linked-list and free resource
149 * (without mutex)
150 */
151 void
152 __snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk)
153 {
154 list_del(&blk->list);
155 hdr->nblocks--;
156 hdr->used -= blk->size;
157 kfree(blk);
158 }
160 /*
161 * free a memory block (with mutex)
162 */
163 int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk)
164 {
165 snd_assert(hdr && blk, return -EINVAL);
167 mutex_lock(&hdr->block_mutex);
168 __snd_util_mem_free(hdr, blk);
169 mutex_unlock(&hdr->block_mutex);
170 return 0;
171 }
173 /*
174 * return available memory size
175 */
176 int snd_util_mem_avail(struct snd_util_memhdr *hdr)
177 {
178 unsigned int size;
179 mutex_lock(&hdr->block_mutex);
180 size = hdr->size - hdr->used;
181 mutex_unlock(&hdr->block_mutex);
182 return size;
183 }
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);
195 /*
196 * INIT part
197 */
199 static int __init alsa_util_mem_init(void)
200 {
201 return 0;
202 }
204 static void __exit alsa_util_mem_exit(void)
205 {
206 }
208 module_init(alsa_util_mem_init)
209 module_exit(alsa_util_mem_exit)