drm: cleanup exit path for module unload

The current sub-module unload exit path is a mess, it tries
to abuse the idr. Just keep a list of devices per driver struct
and free them in-order on rmmod.
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_drv.c

@@ -263,6 +263,8 @@ int drm_init(struct drm_driver *driver)
 
 	DRM_DEBUG("\n");
 
+	INIT_LIST_HEAD(&driver->device_list);
+
 	for (i = 0; driver->pci_driver.id_table[i].vendor != 0; i++) {
 		pid = (struct pci_device_id *)&driver->pci_driver.id_table[i];
 
@@ -334,30 +336,13 @@ static void drm_cleanup(struct drm_device * dev)
 		DRM_ERROR("Cannot unload module\n");
 }
 
-static int drm_minors_cleanup(int id, void *ptr, void *data)
-{
-	struct drm_minor *minor = ptr;
-	struct drm_device *dev;
-	struct drm_driver *driver = data;
-
-	dev = minor->dev;
-	if (minor->dev->driver != driver)
-		return 0;
-
-	if (minor->type != DRM_MINOR_LEGACY)
-		return 0;
-
-	if (dev)
-		pci_dev_put(dev->pdev);
-	drm_cleanup(dev);
-	return 1;
-}
-
 void drm_exit(struct drm_driver *driver)
 {
+	struct drm_device *dev, *tmp;
 	DRM_DEBUG("\n");
 
-	idr_for_each(&drm_minors_idr, &drm_minors_cleanup, driver);
+	list_for_each_entry_safe(dev, tmp, &driver->device_list, driver_item)
+		drm_cleanup(dev);
 
 	DRM_INFO("Module unloaded\n");
 }

drivers/gpu/drm/drm_stub.c

@@ -270,6 +270,8 @@ int drm_get_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
 	if ((ret = drm_get_minor(dev, &dev->primary, DRM_MINOR_LEGACY)))
 		goto err_g2;
 
+	list_add_tail(&dev->driver_item, &driver->device_list);
+
 	DRM_INFO("Initialized %s %d.%d.%d %s on minor %d\n",
 		 driver->name, driver->major, driver->minor, driver->patchlevel,
 		 driver->date, dev->primary->index);

include/drm/drmP.h

@@ -737,6 +737,8 @@ struct drm_driver {
 	int num_ioctls;
 	struct file_operations fops;
 	struct pci_driver pci_driver;
+	/* List of devices hanging off this driver */
+	struct list_head device_list;
 };
 
 #define DRM_MINOR_UNASSIGNED 0
@@ -759,6 +761,7 @@ struct drm_minor {
  * may contain multiple heads.
  */
 struct drm_device {
+	struct list_head driver_item;	/**< list of devices per driver */
 	char *unique;			/**< Unique identifier: e.g., busid */
 	int unique_len;			/**< Length of unique field */
 	char *devname;			/**< For /proc/interrupts */