183 lines
3.7 KiB
C
183 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) 2000 Takashi Iwai <tiwai@suse.de>
|
|
*
|
|
* Generic memory management routines for soundcard memory allocation
|
|
*/
|
|
|
|
#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);
|