drm: remove the dma_ioctl special-case

We might as well have a real ioctl function which checks for the
callbacks. This seems to be a remnant from back in the days when each
drm driver had their own complete ioctl table, with no shared core
drm table at all.

To make really sure no mis-guided user in a kms driver pops up again
explicitly check for that in the new ioctl implementation.

v2: Drop the unused variable I've accidentally left in the code,
spotted by David Herrmann.

Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 15 insertions, 5 deletions

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index f63133b0a9ab..471e051d295e 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -1455,6 +1455,18 @@ int drm_mapbufs(struct drm_device *dev, void *data,
         return retcode;
 }
 
+int drm_dma_ioctl(struct drm_device *dev, void *data,
+                  struct drm_file *file_priv)
+{
+        if (drm_core_check_feature(dev, DRIVER_MODESET))
+                return -EINVAL;
+
+        if (dev->driver->dma_ioctl)
+                return dev->driver->dma_ioctl(dev, data, file_priv);
+        else
+                return -EINVAL;
+}
+
 struct drm_local_map *drm_getsarea(struct drm_device *dev)
 {
         struct drm_map_list *entry;
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index d97976cc51cd..357a14ea3cb0 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -106,8 +106,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
         DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_infobufs, DRM_AUTH),
         DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_mapbufs, DRM_AUTH),
         DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_freebufs, DRM_AUTH),
-        /* The DRM_IOCTL_DMA ioctl should be defined by the driver. */
-        DRM_IOCTL_DEF(DRM_IOCTL_DMA, NULL, DRM_AUTH),
+        DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_dma_ioctl, DRM_AUTH),
 
         DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 
@@ -397,9 +396,6 @@ long drm_ioctl(struct file *filp,
 
         /* Do not trust userspace, use our own definition */
         func = ioctl->func;
-        /* is there a local override? */
-        if ((nr == DRM_IOCTL_NR(DRM_IOCTL_DMA)) && dev->driver->dma_ioctl)
-                func = dev->driver->dma_ioctl;
 
         if (!func) {
                 DRM_DEBUG("no function\n");
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 139d859adf16..808eb237be0e 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1355,6 +1355,8 @@ extern int drm_freebufs(struct drm_device *dev, void *data,
                         struct drm_file *file_priv);
 extern int drm_mapbufs(struct drm_device *dev, void *data,
                        struct drm_file *file_priv);
+extern int drm_dma_ioctl(struct drm_device *dev, void *data,
+                         struct drm_file *file_priv);
 
                                 /* DMA support (drm_dma.h) */
 extern int drm_legacy_dma_setup(struct drm_device *dev);