/************************************************************************** * * 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 <linux/mutex.h> #include <linux/slab.h> #include <linux/module.h> #include "drm_global.h" struct drm_global_item { struct mutex mutex; void *object; int refcount; }; static struct drm_global_item glob[DRM_GLOBAL_NUM]; void drm_global_init(void) { int i; for (i = 0; i < DRM_GLOBAL_NUM; ++i) { struct drm_global_item *item = &glob[i]; mutex_init(&item->mutex); item->object = NULL; item->refcount = 0; } } void drm_global_release(void) { int i; for (i = 0; i < DRM_GLOBAL_NUM; ++i) { struct drm_global_item *item = &glob[i]; BUG_ON(item->object != NULL); BUG_ON(item->refcount != 0); } } int drm_global_item_ref(struct drm_global_reference *ref) { int ret; struct drm_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(drm_global_item_ref); void drm_global_item_unref(struct drm_global_reference *ref) { struct drm_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(drm_global_item_unref);