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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
21#include <linux/mutex.h>
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <linux/module.h>
25#include <sound/core.h>
26#include <sound/util_mem.h>
27
28MODULE_AUTHOR("Takashi Iwai");
29MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation");
30MODULE_LICENSE("GPL");
31
32#define get_memblk(p) list_entry(p, struct snd_util_memblk, list)
33
34/*
35 * create a new memory manager
36 */
37struct snd_util_memhdr *
38snd_util_memhdr_new(int memsize)
39{
40 struct snd_util_memhdr *hdr;
41
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);
48
49 return hdr;
50}
51
52/*
53 * free a memory manager
54 */
55void snd_util_memhdr_free(struct snd_util_memhdr *hdr)
56{
57 struct list_head *p;
58
59 if (!hdr)
60 return;
61 /* release all blocks */
62 while ((p = hdr->block.next) != &hdr->block) {
63 list_del(p);
64 kfree(get_memblk(p));
65 }
66 kfree(hdr);
67}
68
69/*
70 * allocate a memory block (without mutex)
71 */
72struct snd_util_memblk *
73__snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size)
74{
75 struct snd_util_memblk *blk;
76 unsigned int units, prev_offset;
77 struct list_head *p;
78
79 if (snd_BUG_ON(!hdr || size <= 0))
80 return NULL;
81
82 /* word alignment */
83 units = size;
84 if (units & 1)
85 units++;
86 if (units > hdr->size)
87 return NULL;
88
89 /* look for empty block */
90 prev_offset = 0;
91 list_for_each(p, &hdr->block) {
92 blk = get_memblk(p);
93 if (blk->offset - prev_offset >= units)
94 goto __found;
95 prev_offset = blk->offset + blk->size;
96 }
97 if (hdr->size - prev_offset < units)
98 return NULL;
99
100__found:
101 return __snd_util_memblk_new(hdr, units, p->prev);
102}
103
104
105/*
106 * create a new memory block with the given size
107 * the block is linked next to prev
108 */
109struct snd_util_memblk *
110__snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units,
111 struct list_head *prev)
112{
113 struct snd_util_memblk *blk;
114
115 blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size,
116 GFP_KERNEL);
117 if (blk == NULL)
118 return NULL;
119
120 if (prev == &hdr->block)
121 blk->offset = 0;
122 else {
123 struct snd_util_memblk *p = get_memblk(prev);
124 blk->offset = p->offset + p->size;
125 }
126 blk->size = units;
127 list_add(&blk->list, prev);
128 hdr->nblocks++;
129 hdr->used += units;
130 return blk;
131}
132
133
134/*
135 * allocate a memory block (with mutex)
136 */
137struct snd_util_memblk *
138snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size)
139{
140 struct snd_util_memblk *blk;
141 mutex_lock(&hdr->block_mutex);
142 blk = __snd_util_mem_alloc(hdr, size);
143 mutex_unlock(&hdr->block_mutex);
144 return blk;
145}
146
147
148/*
149 * remove the block from linked-list and free resource
150 * (without mutex)
151 */
152void
153__snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk)
154{
155 list_del(&blk->list);
156 hdr->nblocks--;
157 hdr->used -= blk->size;
158 kfree(blk);
159}
160
161/*
162 * free a memory block (with mutex)
163 */
164int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk)
165{
166 if (snd_BUG_ON(!hdr || !blk))
167 return -EINVAL;
168
169 mutex_lock(&hdr->block_mutex);
170 __snd_util_mem_free(hdr, blk);
171 mutex_unlock(&hdr->block_mutex);
172 return 0;
173}
174
175/*
176 * return available memory size
177 */
178int snd_util_mem_avail(struct snd_util_memhdr *hdr)
179{
180 unsigned int size;
181 mutex_lock(&hdr->block_mutex);
182 size = hdr->size - hdr->used;
183 mutex_unlock(&hdr->block_mutex);
184 return size;
185}
186
187
188EXPORT_SYMBOL(snd_util_memhdr_new);
189EXPORT_SYMBOL(snd_util_memhdr_free);
190EXPORT_SYMBOL(snd_util_mem_alloc);
191EXPORT_SYMBOL(snd_util_mem_free);
192EXPORT_SYMBOL(snd_util_mem_avail);
193EXPORT_SYMBOL(__snd_util_mem_alloc);
194EXPORT_SYMBOL(__snd_util_mem_free);
195EXPORT_SYMBOL(__snd_util_memblk_new);
196
197/*
198 * INIT part
199 */
200
201static int __init alsa_util_mem_init(void)
202{
203 return 0;
204}
205
206static void __exit alsa_util_mem_exit(void)
207{
208}
209
210module_init(alsa_util_mem_init)
211module_exit(alsa_util_mem_exit)
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
21#include <linux/mutex.h>
22#include <linux/init.h>
23#include <linux/slab.h>
24#include <sound/core.h>
25#include <sound/util_mem.h>
26
27MODULE_AUTHOR("Takashi Iwai");
28MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation");
29MODULE_LICENSE("GPL");
30
31#define get_memblk(p) list_entry(p, struct snd_util_memblk, list)
32
33/*
34 * create a new memory manager
35 */
36struct snd_util_memhdr *
37snd_util_memhdr_new(int memsize)
38{
39 struct snd_util_memhdr *hdr;
40
41 hdr = kzalloc(sizeof(*hdr), GFP_KERNEL);
42 if (hdr == NULL)
43 return NULL;
44 hdr->size = memsize;
45 mutex_init(&hdr->block_mutex);
46 INIT_LIST_HEAD(&hdr->block);
47
48 return hdr;
49}
50
51/*
52 * free a memory manager
53 */
54void snd_util_memhdr_free(struct snd_util_memhdr *hdr)
55{
56 struct list_head *p;
57
58 if (!hdr)
59 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 */
71struct 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;
77
78 if (snd_BUG_ON(!hdr || size <= 0))
79 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 */
108struct 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;
113
114 blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size,
115 GFP_KERNEL);
116 if (blk == NULL)
117 return NULL;
118
119 if (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}
131
132
133/*
134 * allocate a memory block (with mutex)
135 */
136struct snd_util_memblk *
137snd_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}
145
146
147/*
148 * remove the block from linked-list and free resource
149 * (without mutex)
150 */
151void
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}
159
160/*
161 * free a memory block (with mutex)
162 */
163int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk)
164{
165 if (snd_BUG_ON(!hdr || !blk))
166 return -EINVAL;
167
168 mutex_lock(&hdr->block_mutex);
169 __snd_util_mem_free(hdr, blk);
170 mutex_unlock(&hdr->block_mutex);
171 return 0;
172}
173
174/*
175 * return available memory size
176 */
177int snd_util_mem_avail(struct snd_util_memhdr *hdr)
178{
179 unsigned int size;
180 mutex_lock(&hdr->block_mutex);
181 size = hdr->size - hdr->used;
182 mutex_unlock(&hdr->block_mutex);
183 return size;
184}
185
186
187EXPORT_SYMBOL(snd_util_memhdr_new);
188EXPORT_SYMBOL(snd_util_memhdr_free);
189EXPORT_SYMBOL(snd_util_mem_alloc);
190EXPORT_SYMBOL(snd_util_mem_free);
191EXPORT_SYMBOL(snd_util_mem_avail);
192EXPORT_SYMBOL(__snd_util_mem_alloc);
193EXPORT_SYMBOL(__snd_util_mem_free);
194EXPORT_SYMBOL(__snd_util_memblk_new);
195
196/*
197 * INIT part
198 */
199
200static int __init alsa_util_mem_init(void)
201{
202 return 0;
203}
204
205static void __exit alsa_util_mem_exit(void)
206{
207}
208
209module_init(alsa_util_mem_init)
210module_exit(alsa_util_mem_exit)