| /************************************************************************** |
| * |
| * Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA |
| * All Rights Reserved. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the |
| * "Software"), to deal in the Software without restriction, including |
| * without limitation the rights to use, copy, modify, merge, publish, |
| * distribute, sub license, and/or sell copies of the Software, and to |
| * permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the |
| * next paragraph) shall be included in all copies or substantial portions |
| * of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
| * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, |
| * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
| * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
| * USE OR OTHER DEALINGS IN THE SOFTWARE. |
| * |
| **************************************************************************/ |
| /* |
| * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> |
| */ |
| |
| #include "ttm/ttm_module.h" |
| #include <linux/mutex.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| |
| struct ttm_global_item { |
| struct mutex mutex; |
| void *object; |
| int refcount; |
| }; |
| |
| static struct ttm_global_item glob[TTM_GLOBAL_NUM]; |
| |
| void ttm_global_init(void) |
| { |
| int i; |
| |
| for (i = 0; i < TTM_GLOBAL_NUM; ++i) { |
| struct ttm_global_item *item = &glob[i]; |
| mutex_init(&item->mutex); |
| item->object = NULL; |
| item->refcount = 0; |
| } |
| } |
| |
| void ttm_global_release(void) |
| { |
| int i; |
| for (i = 0; i < TTM_GLOBAL_NUM; ++i) { |
| struct ttm_global_item *item = &glob[i]; |
| BUG_ON(item->object != NULL); |
| BUG_ON(item->refcount != 0); |
| } |
| } |
| |
| int ttm_global_item_ref(struct ttm_global_reference *ref) |
| { |
| int ret; |
| struct ttm_global_item *item = &glob[ref->global_type]; |
| void *object; |
| |
| mutex_lock(&item->mutex); |
| if (item->refcount == 0) { |
| item->object = kzalloc(ref->size, GFP_KERNEL); |
| if (unlikely(item->object == NULL)) { |
| ret = -ENOMEM; |
| goto out_err; |
| } |
| |
| ref->object = item->object; |
| ret = ref->init(ref); |
| if (unlikely(ret != 0)) |
| goto out_err; |
| |
| ++item->refcount; |
| } |
| ref->object = item->object; |
| object = item->object; |
| mutex_unlock(&item->mutex); |
| return 0; |
| out_err: |
| mutex_unlock(&item->mutex); |
| item->object = NULL; |
| return ret; |
| } |
| EXPORT_SYMBOL(ttm_global_item_ref); |
| |
| void ttm_global_item_unref(struct ttm_global_reference *ref) |
| { |
| struct ttm_global_item *item = &glob[ref->global_type]; |
| |
| mutex_lock(&item->mutex); |
| BUG_ON(item->refcount == 0); |
| BUG_ON(ref->object != item->object); |
| if (--item->refcount == 0) { |
| ref->release(ref); |
| item->object = NULL; |
| } |
| mutex_unlock(&item->mutex); |
| } |
| EXPORT_SYMBOL(ttm_global_item_unref); |
| |