[mirror_ubuntu-focal-kernel.git] / sound / synth / util_mem.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);
Commit	Line	Data
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	*/
1da177e4 LT	7
ef9f0a42	8	#include <linux/mutex.h>
1da177e4 LT	9	#include <linux/init.h>
1da177e4 LT	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)
1da177e4 LT	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)
5e246b85 TI	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 *
03da312a TI	60	__snd_util_mem_alloc(struct snd_util_memhdr *hdr, int size)
1da177e4	61	{
03da312a TI	62	struct snd_util_memblk *blk;
03da312a TI	63	unsigned int units, prev_offset;
1da177e4 LT	64	struct list_head *p;
1da177e4 LT	65
5e246b85 TI	66	if (snd_BUG_ON(!hdr \|\| size <= 0))
5e246b85 TI	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 *
03da312a TI	97	__snd_util_memblk_new(struct snd_util_memhdr *hdr, unsigned int units,
1da177e4 LT	98	struct list_head *prev)
1da177e4 LT	99	{
03da312a	100	struct snd_util_memblk *blk;
1da177e4	101
03da312a TI	102	blk = kmalloc(sizeof(struct snd_util_memblk) + hdr->block_extra_size,
03da312a TI	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;
1da177e4 LT	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 *
03da312a TI	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))
5e246b85 TI	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	{
1da177e4 LT	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);