1 files changed, 22 insertions, 11 deletions

diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
index 6dba4b8ce4fe..5370e6b492fd 100644
--- a/drivers/gpu/drm/drm_pci.c
+++ b/drivers/gpu/drm/drm_pci.c
@@ -24,6 +24,8 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
 
@@ -36,6 +38,9 @@
 #include "drm_legacy.h"
 
 #ifdef CONFIG_DRM_LEGACY
+/* List of devices hanging off drivers with stealth attach. */
+static LIST_HEAD(legacy_dev_list);
+static DEFINE_MUTEX(legacy_dev_list_lock);
 
 /**
  * drm_pci_alloc - Allocate a PCI consistent memory block, for DMA.
@@ -196,7 +201,7 @@ static void drm_pci_agp_init(struct drm_device *dev)
 
 static int drm_get_pci_dev(struct pci_dev *pdev,
 			   const struct pci_device_id *ent,
-			   struct drm_driver *driver)
+			   const struct drm_driver *driver)
 {
 	struct drm_device *dev;
 	int ret;
@@ -225,10 +230,11 @@ static int drm_get_pci_dev(struct pci_dev *pdev,
 	if (ret)
 		goto err_agp;
 
-	/* No locking needed since shadow-attach is single-threaded since it may
-	 * only be called from the per-driver module init hook. */
-	if (drm_core_check_feature(dev, DRIVER_LEGACY))
-		list_add_tail(&dev->legacy_dev_list, &driver->legacy_dev_list);
+	if (drm_core_check_feature(dev, DRIVER_LEGACY)) {
+		mutex_lock(&legacy_dev_list_lock);
+		list_add_tail(&dev->legacy_dev_list, &legacy_dev_list);
+		mutex_unlock(&legacy_dev_list_lock);
+	}
 
 	return 0;
 
@@ -249,7 +255,8 @@ err_free:
  *
  * Return: 0 on success or a negative error code on failure.
  */
-int drm_legacy_pci_init(struct drm_driver *driver, struct pci_driver *pdriver)
+int drm_legacy_pci_init(const struct drm_driver *driver,
+			struct pci_driver *pdriver)
 {
 	struct pci_dev *pdev = NULL;
 	const struct pci_device_id *pid;
@@ -261,7 +268,6 @@ int drm_legacy_pci_init(struct drm_driver *driver, struct pci_driver *pdriver)
 		return -EINVAL;
 
 	/* If not using KMS, fall back to stealth mode manual scanning. */
-	INIT_LIST_HEAD(&driver->legacy_dev_list);
 	for (i = 0; pdriver->id_table[i].vendor != 0; i++) {
 		pid = &pdriver->id_table[i];
 
@@ -295,7 +301,8 @@ EXPORT_SYMBOL(drm_legacy_pci_init);
  * Unregister a DRM driver shadow-attached through drm_legacy_pci_init(). This
  * is deprecated and only used by dri1 drivers.
  */
-void drm_legacy_pci_exit(struct drm_driver *driver, struct pci_driver *pdriver)
+void drm_legacy_pci_exit(const struct drm_driver *driver,
+			 struct pci_driver *pdriver)
 {
 	struct drm_device *dev, *tmp;
 
@@ -304,11 +311,15 @@ void drm_legacy_pci_exit(struct drm_driver *driver, struct pci_driver *pdriver)
 	if (!(driver->driver_features & DRIVER_LEGACY)) {
 		WARN_ON(1);
 	} else {
-		list_for_each_entry_safe(dev, tmp, &driver->legacy_dev_list,
+		mutex_lock(&legacy_dev_list_lock);
+		list_for_each_entry_safe(dev, tmp, &legacy_dev_list,
 					 legacy_dev_list) {
-			list_del(&dev->legacy_dev_list);
-			drm_put_dev(dev);
+			if (dev->driver == driver) {
+				list_del(&dev->legacy_dev_list);
+				drm_put_dev(dev);
+			}
 		}
+		mutex_unlock(&legacy_dev_list_lock);
 	}
 	DRM_INFO("Module unloaded\n");
 }