Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 | // 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); |