Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 <sound/driver.h> |
| 22 | #include <linux/init.h> |
| 23 | #include <linux/slab.h> |
| 24 | #include <sound/core.h> |
| 25 | #include <sound/util_mem.h> |
| 26 | |
| 27 | MODULE_AUTHOR("Takashi Iwai"); |
| 28 | MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation"); |
| 29 | MODULE_LICENSE("GPL"); |
| 30 | |
| 31 | #define get_memblk(p) list_entry(p, snd_util_memblk_t, list) |
| 32 | |
| 33 | /* |
| 34 | * create a new memory manager |
| 35 | */ |
| 36 | snd_util_memhdr_t * |
| 37 | snd_util_memhdr_new(int memsize) |
| 38 | { |
| 39 | snd_util_memhdr_t *hdr; |
| 40 | |
Takashi Iwai | 561b220 | 2005-09-09 14:22:34 +0200 | [diff] [blame^] | 41 | hdr = kzalloc(sizeof(*hdr), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | if (hdr == NULL) |
| 43 | return NULL; |
| 44 | hdr->size = memsize; |
| 45 | init_MUTEX(&hdr->block_mutex); |
| 46 | INIT_LIST_HEAD(&hdr->block); |
| 47 | |
| 48 | return hdr; |
| 49 | } |
| 50 | |
| 51 | /* |
| 52 | * free a memory manager |
| 53 | */ |
| 54 | void snd_util_memhdr_free(snd_util_memhdr_t *hdr) |
| 55 | { |
| 56 | struct list_head *p; |
| 57 | |
| 58 | snd_assert(hdr != NULL, return); |
| 59 | /* release all blocks */ |
| 60 | while ((p = hdr->block.next) != &hdr->block) { |
| 61 | list_del(p); |
| 62 | kfree(get_memblk(p)); |
| 63 | } |
| 64 | kfree(hdr); |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * allocate a memory block (without mutex) |
| 69 | */ |
| 70 | snd_util_memblk_t * |
| 71 | __snd_util_mem_alloc(snd_util_memhdr_t *hdr, int size) |
| 72 | { |
| 73 | snd_util_memblk_t *blk; |
| 74 | snd_util_unit_t units, prev_offset; |
| 75 | struct list_head *p; |
| 76 | |
| 77 | snd_assert(hdr != NULL, return NULL); |
| 78 | snd_assert(size > 0, return NULL); |
| 79 | |
| 80 | /* word alignment */ |
| 81 | units = size; |
| 82 | if (units & 1) |
| 83 | units++; |
| 84 | if (units > hdr->size) |
| 85 | return NULL; |
| 86 | |
| 87 | /* look for empty block */ |
| 88 | prev_offset = 0; |
| 89 | list_for_each(p, &hdr->block) { |
| 90 | blk = get_memblk(p); |
| 91 | if (blk->offset - prev_offset >= units) |
| 92 | goto __found; |
| 93 | prev_offset = blk->offset + blk->size; |
| 94 | } |
| 95 | if (hdr->size - prev_offset < units) |
| 96 | return NULL; |
| 97 | |
| 98 | __found: |
| 99 | return __snd_util_memblk_new(hdr, units, p->prev); |
| 100 | } |
| 101 | |
| 102 | |
| 103 | /* |
| 104 | * create a new memory block with the given size |
| 105 | * the block is linked next to prev |
| 106 | */ |
| 107 | snd_util_memblk_t * |
| 108 | __snd_util_memblk_new(snd_util_memhdr_t *hdr, snd_util_unit_t units, |
| 109 | struct list_head *prev) |
| 110 | { |
| 111 | snd_util_memblk_t *blk; |
| 112 | |
| 113 | blk = kmalloc(sizeof(snd_util_memblk_t) + hdr->block_extra_size, GFP_KERNEL); |
| 114 | if (blk == NULL) |
| 115 | return NULL; |
| 116 | |
| 117 | if (! prev || prev == &hdr->block) |
| 118 | blk->offset = 0; |
| 119 | else { |
| 120 | snd_util_memblk_t *p = get_memblk(prev); |
| 121 | blk->offset = p->offset + p->size; |
| 122 | } |
| 123 | blk->size = units; |
| 124 | list_add(&blk->list, prev); |
| 125 | hdr->nblocks++; |
| 126 | hdr->used += units; |
| 127 | return blk; |
| 128 | } |
| 129 | |
| 130 | |
| 131 | /* |
| 132 | * allocate a memory block (with mutex) |
| 133 | */ |
| 134 | snd_util_memblk_t * |
| 135 | snd_util_mem_alloc(snd_util_memhdr_t *hdr, int size) |
| 136 | { |
| 137 | snd_util_memblk_t *blk; |
| 138 | down(&hdr->block_mutex); |
| 139 | blk = __snd_util_mem_alloc(hdr, size); |
| 140 | up(&hdr->block_mutex); |
| 141 | return blk; |
| 142 | } |
| 143 | |
| 144 | |
| 145 | /* |
| 146 | * remove the block from linked-list and free resource |
| 147 | * (without mutex) |
| 148 | */ |
| 149 | void |
| 150 | __snd_util_mem_free(snd_util_memhdr_t *hdr, snd_util_memblk_t *blk) |
| 151 | { |
| 152 | list_del(&blk->list); |
| 153 | hdr->nblocks--; |
| 154 | hdr->used -= blk->size; |
| 155 | kfree(blk); |
| 156 | } |
| 157 | |
| 158 | /* |
| 159 | * free a memory block (with mutex) |
| 160 | */ |
| 161 | int snd_util_mem_free(snd_util_memhdr_t *hdr, snd_util_memblk_t *blk) |
| 162 | { |
| 163 | snd_assert(hdr && blk, return -EINVAL); |
| 164 | |
| 165 | down(&hdr->block_mutex); |
| 166 | __snd_util_mem_free(hdr, blk); |
| 167 | up(&hdr->block_mutex); |
| 168 | return 0; |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * return available memory size |
| 173 | */ |
| 174 | int snd_util_mem_avail(snd_util_memhdr_t *hdr) |
| 175 | { |
| 176 | unsigned int size; |
| 177 | down(&hdr->block_mutex); |
| 178 | size = hdr->size - hdr->used; |
| 179 | up(&hdr->block_mutex); |
| 180 | return size; |
| 181 | } |
| 182 | |
| 183 | |
| 184 | EXPORT_SYMBOL(snd_util_memhdr_new); |
| 185 | EXPORT_SYMBOL(snd_util_memhdr_free); |
| 186 | EXPORT_SYMBOL(snd_util_mem_alloc); |
| 187 | EXPORT_SYMBOL(snd_util_mem_free); |
| 188 | EXPORT_SYMBOL(snd_util_mem_avail); |
| 189 | EXPORT_SYMBOL(__snd_util_mem_alloc); |
| 190 | EXPORT_SYMBOL(__snd_util_mem_free); |
| 191 | EXPORT_SYMBOL(__snd_util_memblk_new); |
| 192 | |
| 193 | /* |
| 194 | * INIT part |
| 195 | */ |
| 196 | |
| 197 | static int __init alsa_util_mem_init(void) |
| 198 | { |
| 199 | return 0; |
| 200 | } |
| 201 | |
| 202 | static void __exit alsa_util_mem_exit(void) |
| 203 | { |
| 204 | } |
| 205 | |
| 206 | module_init(alsa_util_mem_init) |
| 207 | module_exit(alsa_util_mem_exit) |