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Diffstat (limited to '')
| -rw-r--r-- | sound/synth/util_mem.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/sound/synth/util_mem.c b/sound/synth/util_mem.c new file mode 100644 index 000000000..4bd1e9820 --- /dev/null +++ b/sound/synth/util_mem.c @@ -0,0 +1,195 @@ +/* + * Copyright (C) 2000 Takashi Iwai <tiwai@suse.de> + * + * Generic memory management routines for soundcard memory allocation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/mutex.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <sound/core.h> +#include <sound/util_mem.h> + +MODULE_AUTHOR("Takashi Iwai"); +MODULE_DESCRIPTION("Generic memory management routines for soundcard memory allocation"); +MODULE_LICENSE("GPL"); + +#define get_memblk(p) list_entry(p, struct snd_util_memblk, list) + +/* + * create a new memory manager + */ +struct snd_util_memhdr * +snd_util_memhdr_new(int memsize) +{ + struct snd_util_memhdr *hdr; + + hdr = kzalloc(sizeof(*hdr), GFP_KERNEL); + if (hdr == NULL) + return NULL; + hdr->size = memsize; + mutex_init(&hdr->block_mutex); + INIT_LIST_HEAD(&hdr->block); + + return hdr; +} + +/* + * free a memory manager + */ +void snd_util_memhdr_free(struct snd_util_memhdr *hdr) +{ + struct list_head *p; + + if (!hdr) + return; + /* release all blocks */ + while ((p = hdr->block.next) != &hdr->block) { + list_del(p); + kfree(get_memblk(p)); + } + kfree(hdr); +} + +/* + * allocate a memory block (without mutex) + */ +struct snd_util_memblk * +__snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) +{ + struct snd_util_memblk *blk; + unsigned int units, prev_offset; + struct list_head *p; + + if (snd_BUG_ON(!hdr || size <= 0)) + return NULL; + + /* word alignment */ + units = size; + if (units & 1) + units++; + if (units > hdr->size) + return NULL; + + /* look for empty block */ + prev_offset = 0; + list_for_each(p, &hdr->block) { + blk = get_memblk(p); + if (blk->offset - prev_offset >= units) + goto __found; + prev_offset = blk->offset + blk->size; + } + if (hdr->size - prev_offset < units) + return NULL; + +__found: + return __snd_util_memblk_new(hdr, units, p->prev); +} + + +/* + * create a new memory block with the given size + * the block is linked next to prev + */ +struct snd_util_memblk * +__snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units, + struct list_head *prev) +{ + struct snd_util_memblk *blk; + + blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size, + GFP_KERNEL); + if (blk == NULL) + return NULL; + + if (prev == &hdr->block) + blk->offset = 0; + else { + struct snd_util_memblk *p = get_memblk(prev); + blk->offset = p->offset + p->size; + } + blk->size = units; + list_add(&blk->list, prev); + hdr->nblocks++; + hdr->used += units; + return blk; +} + + +/* + * allocate a memory block (with mutex) + */ +struct snd_util_memblk * +snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size) +{ + struct snd_util_memblk *blk; + mutex_lock(&hdr->block_mutex); + blk = __snd_util_mem_alloc(hdr, size); + mutex_unlock(&hdr->block_mutex); + return blk; +} + + +/* + * remove the block from linked-list and free resource + * (without mutex) + */ +void +__snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) +{ + list_del(&blk->list); + hdr->nblocks--; + hdr->used -= blk->size; + kfree(blk); +} + +/* + * free a memory block (with mutex) + */ +int snd_util_mem_free(struct snd_util_memhdr *hdr, struct snd_util_memblk *blk) +{ + if (snd_BUG_ON(!hdr || !blk)) + return -EINVAL; + + mutex_lock(&hdr->block_mutex); + __snd_util_mem_free(hdr, blk); + mutex_unlock(&hdr->block_mutex); + return 0; +} + +/* + * return available memory size + */ +int snd_util_mem_avail(struct snd_util_memhdr *hdr) +{ + unsigned int size; + mutex_lock(&hdr->block_mutex); + size = hdr->size - hdr->used; + mutex_unlock(&hdr->block_mutex); + return size; +} + + +EXPORT_SYMBOL(snd_util_memhdr_new); +EXPORT_SYMBOL(snd_util_memhdr_free); +EXPORT_SYMBOL(snd_util_mem_alloc); +EXPORT_SYMBOL(snd_util_mem_free); +EXPORT_SYMBOL(snd_util_mem_avail); +EXPORT_SYMBOL(__snd_util_mem_alloc); +EXPORT_SYMBOL(__snd_util_mem_free); +EXPORT_SYMBOL(__snd_util_memblk_new); |