sys/dev/drm/drm_fops.c

   1 /*-
   2  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
   3  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  * Authors:
  26  *    Rickard E. (Rik) Faith <faith@valinux.com>
  27  *    Daryll Strauss <daryll@valinux.com>
  28  *    Gareth Hughes <gareth@valinux.com>
  29  *
  30  */
  31
  32 /** @file drm_fops.c
  33  * Support code for dealing with the file privates associated with each
  34  * open of the DRM device.
  35  */
  36
  37 #include "dev/drm/drmP.h"
  38
  39 struct drm_file *drm_find_file_by_proc(struct drm_device *dev, DRM_STRUCTPROC *p)
  40 {
  41         uid_t uid = p->td_proc->p_ucred->cr_svuid;
  42         pid_t pid = p->td_proc->p_pid;
  43         struct drm_file *priv;
  44
  45         TAILQ_FOREACH(priv, &dev->files, link)
  46                 if (priv->pid == pid && priv->uid == uid)
  47                         return priv;
  48         return NULL;
  49 }
  50
  51 /* drm_open_helper is called whenever a process opens /dev/drm. */
  52 int drm_open_helper(struct cdev *kdev, int flags, int fmt, DRM_STRUCTPROC *p,
  53                     struct drm_device *dev)
  54 {
  55         struct drm_file *priv;
  56         int m = minor(kdev);
  57         int retcode;
  58
  59         if (flags & O_EXCL)
  60                 return EBUSY; /* No exclusive opens */
  61         dev->flags = flags;
  62
  63         DRM_DEBUG("pid = %d, minor = %d\n", DRM_CURRENTPID, m);
  64         DRM_LOCK();
  65         priv = drm_find_file_by_proc(dev, p);
  66         if (priv) {
  67                 priv->refs++;
  68         } else {
  69                 priv = malloc(sizeof(*priv), DRM_MEM_FILES, M_NOWAIT | M_ZERO);
  70                 if (priv == NULL) {
  71                         DRM_UNLOCK();
  72                         return ENOMEM;
  73                 }
  74                 priv->uid               = p->td_proc->p_ucred->cr_svuid;
  75                 priv->pid               = p->td_proc->p_pid;
  76                 priv->refs              = 1;
  77                 priv->minor             = m;
  78                 priv->ioctl_count       = 0;
  79
  80                 /* for compatibility root is always authenticated */
  81                 priv->authenticated     = DRM_SUSER(p);
  82
  83                 if (dev->driver->open) {
  84                         /* shared code returns -errno */
  85                         retcode = -dev->driver->open(dev, priv);
  86                         if (retcode != 0) {
  87                                 free(priv, DRM_MEM_FILES);
  88                                 DRM_UNLOCK();
  89                                 return retcode;
  90                         }
  91                 }
  92
  93                 /* first opener automatically becomes master */
  94                 priv->master = TAILQ_EMPTY(&dev->files);
  95
  96                 TAILQ_INSERT_TAIL(&dev->files, priv, link);
  97         }
  98
  99         DRM_UNLOCK();
 100         kdev->si_drv1 = dev;
 101         return 0;
 102 }
 103
 104
 105 /* The drm_read and drm_poll are stubs to prevent spurious errors
 106  * on older X Servers (4.3.0 and earlier) */
 107 int drm_read(struct dev_read_args *ap)
 108 {
 109         return 0;
 110 }
 111
 112 int drm_poll(struct dev_poll_args *ap)
 113 {
 114         return 0;
 115 }