drm: add hotspot support for cursors.

So it looks like for virtual hw cursors on QXL we need to inform
the "hw" device what the cursor hotspot parameters are. This
makes sense if you think the host has to draw the cursor and interpret
clicks from it. However the current modesetting interface doesn't support
passing the hotspot information from userspace.

This implements a new cursor ioctl, that takes the hotspot info as well,
userspace can try calling the new interface and if it gets -ENOSYS it means
its on an older kernel and can just fallback.

Reviewed-by: Daniel Vetter <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/drm_crtc.c

···
 	return ret;
 }
 
-int drm_mode_cursor_ioctl(struct drm_device *dev,
-			void *data, struct drm_file *file_priv)
+static int drm_mode_cursor_common(struct drm_device *dev,
+				  struct drm_mode_cursor2 *req,
+				  struct drm_file *file_priv)
 {
-	struct drm_mode_cursor *req = data;
 	struct drm_mode_object *obj;
 	struct drm_crtc *crtc;
 	int ret = 0;
···
 
 	mutex_lock(&crtc->mutex);
 	if (req->flags & DRM_MODE_CURSOR_BO) {
-		if (!crtc->funcs->cursor_set) {
+		if (!crtc->funcs->cursor_set && !crtc->funcs->cursor_set2) {
 			ret = -ENXIO;
 			goto out;
 		}
 		/* Turns off the cursor if handle is 0 */
-		ret = crtc->funcs->cursor_set(crtc, file_priv, req->handle,
-					      req->width, req->height);
+		if (crtc->funcs->cursor_set2)
+			ret = crtc->funcs->cursor_set2(crtc, file_priv, req->handle,
+						      req->width, req->height, req->hot_x, req->hot_y);
+		else
+			ret = crtc->funcs->cursor_set(crtc, file_priv, req->handle,
+						      req->width, req->height);
 	}
 
 	if (req->flags & DRM_MODE_CURSOR_MOVE) {
···
 	mutex_unlock(&crtc->mutex);
 
 	return ret;
+
+}
+int drm_mode_cursor_ioctl(struct drm_device *dev,
+			void *data, struct drm_file *file_priv)
+{
+	struct drm_mode_cursor *req = data;
+	struct drm_mode_cursor2 new_req;
+
+	memcpy(&new_req, req, sizeof(struct drm_mode_cursor));
+	new_req.hot_x = new_req.hot_y = 0;
+
+	return drm_mode_cursor_common(dev, &new_req, file_priv);
+}
+
+int drm_mode_cursor2_ioctl(struct drm_device *dev,
+			   void *data, struct drm_file *file_priv)
+{
+	struct drm_mode_cursor2 *req = data;
+	return drm_mode_cursor_common(dev, req, file_priv);
 }
 
 /* Original addfb only supported RGB formats, so figure out which one */

drivers/gpu/drm/drm_drv.c

···
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
+	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 };
 
 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )

include/drm/drm_crtc.h

···
 	/* cursor controls */
 	int (*cursor_set)(struct drm_crtc *crtc, struct drm_file *file_priv,
 			  uint32_t handle, uint32_t width, uint32_t height);
+	int (*cursor_set2)(struct drm_crtc *crtc, struct drm_file *file_priv,
+			   uint32_t handle, uint32_t width, uint32_t height,
+			   int32_t hot_x, int32_t hot_y);
 	int (*cursor_move)(struct drm_crtc *crtc, int x, int y);
 
 	/* Set gamma on the CRTC */
···
 extern int drm_mode_setplane(struct drm_device *dev,
 			       void *data, struct drm_file *file_priv);
 extern int drm_mode_cursor_ioctl(struct drm_device *dev,
+				void *data, struct drm_file *file_priv);
+extern int drm_mode_cursor2_ioctl(struct drm_device *dev,
 				void *data, struct drm_file *file_priv);
 extern int drm_mode_addfb(struct drm_device *dev,
 			  void *data, struct drm_file *file_priv);

include/uapi/drm/drm.h

···
 #define DRM_IOCTL_MODE_ADDFB2		DRM_IOWR(0xB8, struct drm_mode_fb_cmd2)
 #define DRM_IOCTL_MODE_OBJ_GETPROPERTIES	DRM_IOWR(0xB9, struct drm_mode_obj_get_properties)
 #define DRM_IOCTL_MODE_OBJ_SETPROPERTY	DRM_IOWR(0xBA, struct drm_mode_obj_set_property)
+#define DRM_IOCTL_MODE_CURSOR2		DRM_IOWR(0xBB, struct drm_mode_cursor2)
 
 /**
  * Device specific ioctls should only be in their respective headers

include/uapi/drm/drm_mode.h

···
 	__u32 handle;
 };
 
+struct drm_mode_cursor2 {
+	__u32 flags;
+	__u32 crtc_id;
+	__s32 x;
+	__s32 y;
+	__u32 width;
+	__u32 height;
+	/* driver specific handle */
+	__u32 handle;
+	__s32 hot_x;
+	__s32 hot_y;
+};
+
 struct drm_mode_crtc_lut {
 	__u32 crtc_id;
 	__u32 gamma_size;