linux/sound/synth/util_mem.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

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);