Line data    Source code

       1             : /*      $OpenBSD: drm_global.c,v 1.3 2015/09/23 23:12:11 kettenis Exp $ */
       2             : /**************************************************************************
       3             :  *
       4             :  * Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA
       5             :  * All Rights Reserved.
       6             :  *
       7             :  * Permission is hereby granted, free of charge, to any person obtaining a
       8             :  * copy of this software and associated documentation files (the
       9             :  * "Software"), to deal in the Software without restriction, including
      10             :  * without limitation the rights to use, copy, modify, merge, publish,
      11             :  * distribute, sub license, and/or sell copies of the Software, and to
      12             :  * permit persons to whom the Software is furnished to do so, subject to
      13             :  * the following conditions:
      14             :  *
      15             :  * The above copyright notice and this permission notice (including the
      16             :  * next paragraph) shall be included in all copies or substantial portions
      17             :  * of the Software.
      18             :  *
      19             :  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      20             :  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      21             :  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
      22             :  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
      23             :  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
      24             :  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
      25             :  * USE OR OTHER DEALINGS IN THE SOFTWARE.
      26             :  *
      27             :  **************************************************************************/
      28             : /*
      29             :  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
      30             :  */
      31             : 
      32             : #include <dev/pci/drm/drmP.h>
      33             : #include <dev/pci/drm/drm_global.h>
      34             : #include <sys/rwlock.h>
      35             : 
      36             : struct drm_global_item {
      37             :         struct rwlock mutex;
      38             :         void *object;
      39             :         int refcount;
      40             : };
      41             : 
      42             : static struct drm_global_item glob[DRM_GLOBAL_NUM];
      43             : 
      44           0 : void drm_global_init(void)
      45             : {
      46             :         int i;
      47             : 
      48           0 :         for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
      49           0 :                 struct drm_global_item *item = &glob[i];
      50           0 :                 rw_init(&item->mutex, "gblitm");
      51           0 :                 item->object = NULL;
      52           0 :                 item->refcount = 0;
      53             :         }
      54           0 : }
      55             : 
      56           0 : void drm_global_release(void)
      57             : {
      58             :         int i;
      59           0 :         for (i = 0; i < DRM_GLOBAL_NUM; ++i) {
      60           0 :                 struct drm_global_item *item = &glob[i];
      61           0 :                 BUG_ON(item->object != NULL);
      62           0 :                 BUG_ON(item->refcount != 0);
      63             :         }
      64           0 : }
      65             : 
      66           0 : int drm_global_item_ref(struct drm_global_reference *ref)
      67             : {
      68             :         int ret;
      69           0 :         struct drm_global_item *item = &glob[ref->global_type];
      70             : 
      71           0 :         mutex_lock(&item->mutex);
      72           0 :         if (item->refcount == 0) {
      73           0 :                 item->object = kzalloc(ref->size, GFP_KERNEL);
      74           0 :                 if (unlikely(item->object == NULL)) {
      75             :                         ret = -ENOMEM;
      76           0 :                         goto out_err;
      77             :                 }
      78             : 
      79           0 :                 ref->object = item->object;
      80           0 :                 ret = ref->init(ref);
      81           0 :                 if (unlikely(ret != 0))
      82             :                         goto out_err;
      83             : 
      84             :         }
      85           0 :         ++item->refcount;
      86           0 :         ref->object = item->object;
      87           0 :         mutex_unlock(&item->mutex);
      88           0 :         return 0;
      89             : out_err:
      90           0 :         mutex_unlock(&item->mutex);
      91           0 :         item->object = NULL;
      92           0 :         return ret;
      93           0 : }
      94             : EXPORT_SYMBOL(drm_global_item_ref);
      95             : 
      96           0 : void drm_global_item_unref(struct drm_global_reference *ref)
      97             : {
      98           0 :         struct drm_global_item *item = &glob[ref->global_type];
      99             : 
     100           0 :         mutex_lock(&item->mutex);
     101           0 :         BUG_ON(item->refcount == 0);
     102           0 :         BUG_ON(ref->object != item->object);
     103           0 :         if (--item->refcount == 0) {
     104           0 :                 ref->release(ref);
     105           0 :                 item->object = NULL;
     106           0 :         }
     107           0 :         mutex_unlock(&item->mutex);
     108           0 : }
     109             : EXPORT_SYMBOL(drm_global_item_unref);
     110             :