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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2000 Takashi Iwai <tiwai@suse.de>
4 *
5 * Generic memory management routines for soundcard memory allocation
6 */
7
8#include <linux/mutex.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/module.h>
12#include <sound/core.h>
13#include <sound/util_mem.h>
14
15MODULE_AUTHOR("Takashi Iwai");
16MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation");
17MODULE_LICENSE("GPL");
18
19#define get_memblk(p) list_entry(p, struct snd_util_memblk, list)
20
21/*
22 * create a new memory manager
23 */
24struct snd_util_memhdr *
25snd_util_memhdr_new(int memsize)
26{
27 struct snd_util_memhdr *hdr;
28
29 hdr = kzalloc(sizeof(*hdr), GFP_KERNEL);
30 if (hdr == NULL)
31 return NULL;
32 hdr->size = memsize;
33 mutex_init(&hdr->block_mutex);
34 INIT_LIST_HEAD(&hdr->block);
35
36 return hdr;
37}
38
39/*
40 * free a memory manager
41 */
42void snd_util_memhdr_free(struct snd_util_memhdr *hdr)
43{
44 struct list_head *p;
45
46 if (!hdr)
47 return;
48 /* release all blocks */
49 while ((p = hdr->block.next) != &hdr->block) {
50 list_del(p);
51 kfree(get_memblk(p));
52 }
53 kfree(hdr);
54}
55
56/*
57 * allocate a memory block (without mutex)
58 */
59struct snd_util_memblk *
60__snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size)
61{
62 struct snd_util_memblk *blk;
63 unsigned int units, prev_offset;
64 struct list_head *p;
65
66 if (snd_BUG_ON(!hdr || size <= 0))
67 return NULL;
68
69 /* word alignment */
70 units = size;
71 if (units & 1)
72 units++;
73 if (units > hdr->size)
74 return NULL;
75
76 /* look for empty block */
77 prev_offset = 0;
78 list_for_each(p, &hdr->block) {
79 blk = get_memblk(p);
80 if (blk->offset - prev_offset >= units)
81 goto __found;
82 prev_offset = blk->offset + blk->size;
83 }
84 if (hdr->size - prev_offset < units)
85 return NULL;
86
87__found:
88 return __snd_util_memblk_new(hdr, units, p->prev);
89}
90
91
92/*
93 * create a new memory block with the given size
94 * the block is linked next to prev
95 */
96struct snd_util_memblk *
97__snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units,
98 struct list_head *prev)
99{
100 struct snd_util_memblk *blk;
101
102 blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size,
103 GFP_KERNEL);
104 if (blk == NULL)
105 return NULL;
106
107 if (prev == &hdr->block)
108 blk->offset = 0;
109 else {
110 struct snd_util_memblk *p = get_memblk(prev);
111 blk->offset = p->offset + p->size;
112 }
113 blk->size = units;
114 list_add(&blk->list, prev);
115 hdr->nblocks++;
116 hdr->used += units;
117 return blk;
118}
119
120
121/*
122 * allocate a memory block (with mutex)
123 */
124struct snd_util_memblk *
125snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size)
126{
127 struct snd_util_memblk *blk;
128 mutex_lock(&hdr->block_mutex);
129 blk = __snd_util_mem_alloc(hdr, size);
130 mutex_unlock(&hdr->block_mutex);
131 return blk;
132}
133
134
135/*
136 * remove the block from linked-list and free resource
137 * (without mutex)
138 */
139void
140__snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk)
141{
142 list_del(&blk->list);
143 hdr->nblocks--;
144 hdr->used -= blk->size;
145 kfree(blk);
146}
147
148/*
149 * free a memory block (with mutex)
150 */
151int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk)
152{
153 if (snd_BUG_ON(!hdr || !blk))
154 return -EINVAL;
155
156 mutex_lock(&hdr->block_mutex);
157 __snd_util_mem_free(hdr, blk);
158 mutex_unlock(&hdr->block_mutex);
159 return 0;
160}
161
162/*
163 * return available memory size
164 */
165int snd_util_mem_avail(struct snd_util_memhdr *hdr)
166{
167 unsigned int size;
168 mutex_lock(&hdr->block_mutex);
169 size = hdr->size - hdr->used;
170 mutex_unlock(&hdr->block_mutex);
171 return size;
172}
173
174
175EXPORT_SYMBOL(snd_util_memhdr_new);
176EXPORT_SYMBOL(snd_util_memhdr_free);
177EXPORT_SYMBOL(snd_util_mem_alloc);
178EXPORT_SYMBOL(snd_util_mem_free);
179EXPORT_SYMBOL(snd_util_mem_avail);
180EXPORT_SYMBOL(__snd_util_mem_alloc);
181EXPORT_SYMBOL(__snd_util_mem_free);
182EXPORT_SYMBOL(__snd_util_memblk_new);
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)