/* * 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 <sound/driver.h> #include <linux/init.h> #include <linux/slab.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; init_MUTEX(&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; snd_assert(hdr != NULL, 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; snd_assert(hdr != NULL, return NULL); snd_assert(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 || 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; down(&hdr->block_mutex); blk = __snd_util_mem_alloc(hdr, size); up(&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) { snd_assert(hdr && blk, return -EINVAL); down(&hdr->block_mutex); __snd_util_mem_free(hdr, blk); up(&hdr->block_mutex); return 0; } /* * return available memory size */ int snd_util_mem_avail(struct snd_util_memhdr *hdr) { unsigned int size; down(&hdr->block_mutex); size = hdr->size - hdr->used; up(&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)