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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Copyright (C) 2000 Takashi Iwai <tiwai@suse.de> | |
4 | * | |
5 | * Generic memory management routines for soundcard memory allocation | |
1da177e4 LT |
6 | */ |
7 | ||
ef9f0a42 | 8 | #include <linux/mutex.h> |
1da177e4 LT |
9 | #include <linux/init.h> |
10 | #include <linux/slab.h> | |
da155d5b | 11 | #include <linux/module.h> |
1da177e4 LT |
12 | #include <sound/core.h> |
13 | #include <sound/util_mem.h> | |
14 | ||
15 | MODULE_AUTHOR("Takashi Iwai"); | |
16 | MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation"); | |
17 | MODULE_LICENSE("GPL"); | |
18 | ||
03da312a | 19 | #define get_memblk(p) list_entry(p, struct snd_util_memblk, list) |
1da177e4 LT |
20 | |
21 | /* | |
22 | * create a new memory manager | |
23 | */ | |
03da312a | 24 | struct snd_util_memhdr * |
1da177e4 LT |
25 | snd_util_memhdr_new(int memsize) |
26 | { | |
03da312a | 27 | struct snd_util_memhdr *hdr; |
1da177e4 | 28 | |
561b220a | 29 | hdr = kzalloc(sizeof(*hdr), GFP_KERNEL); |
1da177e4 LT |
30 | if (hdr == NULL) |
31 | return NULL; | |
32 | hdr->size = memsize; | |
ef9f0a42 | 33 | mutex_init(&hdr->block_mutex); |
1da177e4 LT |
34 | INIT_LIST_HEAD(&hdr->block); |
35 | ||
36 | return hdr; | |
37 | } | |
38 | ||
39 | /* | |
40 | * free a memory manager | |
41 | */ | |
03da312a | 42 | void snd_util_memhdr_free(struct snd_util_memhdr *hdr) |
1da177e4 LT |
43 | { |
44 | struct list_head *p; | |
45 | ||
5e246b85 TI |
46 | if (!hdr) |
47 | return; | |
1da177e4 LT |
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 | */ | |
03da312a TI |
59 | struct snd_util_memblk * |
60 | __snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) | |
1da177e4 | 61 | { |
03da312a TI |
62 | struct snd_util_memblk *blk; |
63 | unsigned int units, prev_offset; | |
1da177e4 LT |
64 | struct list_head *p; |
65 | ||
5e246b85 TI |
66 | if (snd_BUG_ON(!hdr || size <= 0)) |
67 | return NULL; | |
1da177e4 LT |
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 | */ | |
03da312a TI |
96 | struct snd_util_memblk * |
97 | __snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units, | |
1da177e4 LT |
98 | struct list_head *prev) |
99 | { | |
03da312a | 100 | struct snd_util_memblk *blk; |
1da177e4 | 101 | |
03da312a TI |
102 | blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size, |
103 | GFP_KERNEL); | |
1da177e4 LT |
104 | if (blk == NULL) |
105 | return NULL; | |
106 | ||
8e6c962c | 107 | if (prev == &hdr->block) |
1da177e4 LT |
108 | blk->offset = 0; |
109 | else { | |
03da312a | 110 | struct snd_util_memblk *p = get_memblk(prev); |
1da177e4 LT |
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 | */ | |
03da312a TI |
124 | struct snd_util_memblk * |
125 | snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) | |
1da177e4 | 126 | { |
03da312a | 127 | struct snd_util_memblk *blk; |
ef9f0a42 | 128 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 129 | blk = __snd_util_mem_alloc(hdr, size); |
ef9f0a42 | 130 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
131 | return blk; |
132 | } | |
133 | ||
134 | ||
135 | /* | |
136 | * remove the block from linked-list and free resource | |
137 | * (without mutex) | |
138 | */ | |
139 | void | |
03da312a | 140 | __snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) |
1da177e4 LT |
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 | */ | |
03da312a | 151 | int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) |
1da177e4 | 152 | { |
5e246b85 TI |
153 | if (snd_BUG_ON(!hdr || !blk)) |
154 | return -EINVAL; | |
1da177e4 | 155 | |
ef9f0a42 | 156 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 157 | __snd_util_mem_free(hdr, blk); |
ef9f0a42 | 158 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
159 | return 0; |
160 | } | |
161 | ||
162 | /* | |
163 | * return available memory size | |
164 | */ | |
03da312a | 165 | int snd_util_mem_avail(struct snd_util_memhdr *hdr) |
1da177e4 LT |
166 | { |
167 | unsigned int size; | |
ef9f0a42 | 168 | mutex_lock(&hdr->block_mutex); |
1da177e4 | 169 | size = hdr->size - hdr->used; |
ef9f0a42 | 170 | mutex_unlock(&hdr->block_mutex); |
1da177e4 LT |
171 | return size; |
172 | } | |
173 | ||
174 | ||
175 | EXPORT_SYMBOL(snd_util_memhdr_new); | |
176 | EXPORT_SYMBOL(snd_util_memhdr_free); | |
177 | EXPORT_SYMBOL(snd_util_mem_alloc); | |
178 | EXPORT_SYMBOL(snd_util_mem_free); | |
179 | EXPORT_SYMBOL(snd_util_mem_avail); | |
180 | EXPORT_SYMBOL(__snd_util_mem_alloc); | |
181 | EXPORT_SYMBOL(__snd_util_mem_free); | |
182 | EXPORT_SYMBOL(__snd_util_memblk_new); |