6 files changed, 57 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index d166bd080400..0b65fbc8a630 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -390,6 +390,10 @@ long drm_ioctl(struct file *filp,
         unsigned int usize, asize;
 
         dev = file_priv->minor->dev;
+
+        if (drm_device_is_unplugged(dev))
+                return -ENODEV;
+
         atomic_inc(&dev->ioctl_count);
         atomic_inc(&dev->counts[_DRM_STAT_IOCTLS]);
         ++file_priv->ioctl_count;
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 6263b0147598..7348a3dab250 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -133,6 +133,9 @@ int drm_open(struct inode *inode, struct file *filp)
         if (!(dev = minor->dev))
                 return -ENODEV;
 
+        if (drm_device_is_unplugged(dev))
+                return -ENODEV;
+
         retcode = drm_open_helper(inode, filp, dev);
         if (!retcode) {
                 atomic_inc(&dev->counts[_DRM_STAT_OPENS]);
@@ -181,6 +184,9 @@ int drm_stub_open(struct inode *inode, struct file *filp)
         if (!(dev = minor->dev))
                 goto out;
 
+        if (drm_device_is_unplugged(dev))
+                goto out;
+
         old_fops = filp->f_op;
         filp->f_op = fops_get(dev->driver->fops);
         if (filp->f_op == NULL) {
@@ -579,6 +585,8 @@ int drm_release(struct inode *inode, struct file *filp)
                         retcode = -EBUSY;
                 } else
                         retcode = drm_lastclose(dev);
+                if (drm_device_is_unplugged(dev))
+                        drm_put_dev(dev);
         }
         mutex_unlock(&drm_global_mutex);
 
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 3ebe3c8f58b5..0ef358e53245 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -661,6 +661,9 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
         struct drm_hash_item *hash;
         int ret = 0;
 
+        if (drm_device_is_unplugged(dev))
+                return -ENODEV;
+
         mutex_lock(&dev->struct_mutex);
 
         if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index 6d7b083c5b77..bbd40eaf9821 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -429,6 +429,11 @@ int drm_put_minor(struct drm_minor **minor_p)
         return 0;
 }
 
+static void drm_unplug_minor(struct drm_minor *minor)
+{
+        drm_sysfs_device_remove(minor);
+}
+
 /**
  * Called via drm_exit() at module unload time or when pci device is
  * unplugged.
@@ -492,3 +497,21 @@ void drm_put_dev(struct drm_device *dev)
         kfree(dev);
 }
 EXPORT_SYMBOL(drm_put_dev);
+
+void drm_unplug_dev(struct drm_device *dev)
+{
+        /* for a USB device */
+        if (drm_core_check_feature(dev, DRIVER_MODESET))
+                drm_unplug_minor(dev->control);
+        drm_unplug_minor(dev->primary);
+
+        mutex_lock(&drm_global_mutex);
+
+        drm_device_set_unplugged(dev);
+
+        if (dev->open_count == 0) {
+                drm_put_dev(dev);
+        }
+        mutex_unlock(&drm_global_mutex);
+}
+EXPORT_SYMBOL(drm_unplug_dev);
diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index 55cd61567812..149561818349 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -680,6 +680,9 @@ int drm_mmap(struct file *filp, struct vm_area_struct *vma)
         struct drm_device *dev = priv->minor->dev;
         int ret;
 
+        if (drm_device_is_unplugged(dev))
+                return -ENODEV;
+
         mutex_lock(&dev->struct_mutex);
         ret = drm_mmap_locked(filp, vma);
         mutex_unlock(&dev->struct_mutex);
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index cfd921ff0cc4..574bd1c81ebd 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1170,6 +1170,8 @@ struct drm_device {
         struct idr object_name_idr;
         /*@} */
         int switch_power_state;
+
+        atomic_t unplugged; /* device has been unplugged or gone away */
 };
 
 #define DRM_SWITCH_POWER_ON 0
@@ -1235,6 +1237,19 @@ static inline int drm_mtrr_del(int handle, unsigned long offset,
 }
 #endif
 
+static inline void drm_device_set_unplugged(struct drm_device *dev)
+{
+        smp_wmb();
+        atomic_set(&dev->unplugged, 1);
+}
+
+static inline int drm_device_is_unplugged(struct drm_device *dev)
+{
+        int ret = atomic_read(&dev->unplugged);
+        smp_rmb();
+        return ret;
+}
+
 /******************************************************************/
 /** \name Internal function definitions */
 /*@{*/
@@ -1455,6 +1470,7 @@ extern void drm_master_put(struct drm_master **master);
 
 extern void drm_put_dev(struct drm_device *dev);
 extern int drm_put_minor(struct drm_minor **minor);
+extern void drm_unplug_dev(struct drm_device *dev);
 extern unsigned int drm_debug;
 
 extern unsigned int drm_vblank_offdelay;