--- /dev/null
+/*
+ * 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);
+
+/*
+ * INIT part
+ */
+
+static int __init alsa_util_mem_init(void)
+{
+ return 0;
+}
+
+static void __exit alsa_util_mem_exit(void)
+{
+}
+
+module_init(alsa_util_mem_init)
+module_exit(alsa_util_mem_exit)
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