drm: Move property validation to a helper, v2.

Property lifetimes are equal to the device lifetime, so the separate
drm_property_find is not needed. The pointer can be retrieved from
the properties member, which saves us some locking and a extra lookup.
The lifetime for properties is until the device is destroyed, which
happens late in the device unload path.

kms_atomic is also testing for invalid properties which returns -ENOENT,
to be consistent return -ENOENT for valid properties that don't appear
on the object property list.

Changes since v1:
- Return -ENOENT for invalid properties to make kms_atomic pass.
- Change commit message slightly to take this into account.

Testcase: kms_atomic
Testcase: kms_properties
Fixes: 4e9951d96093 ("drm/atomic: Reject properties not part of the object.")
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/599c7fa8-b6fd-a42b-c619-a9e4a9c5c244@linux.intel.com

drivers/gpu/drm/drm_atomic.c

@@ -1609,7 +1609,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
 	struct drm_crtc_state *crtc_state;
 	unsigned plane_mask;
 	int ret = 0;
-	unsigned int i, j, k;
+	unsigned int i, j;
 
 	/* disallow for drivers not supporting atomic: */
 	if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
@@ -1691,16 +1691,7 @@ retry:
 				goto out;
 			}
 
-			for (k = 0; k < obj->properties->count; k++)
-				if (obj->properties->properties[k]->base.id == prop_id)
-					break;
-
-			if (k == obj->properties->count) {
-				ret = -EINVAL;
-				goto out;
-			}
-
-			prop = drm_property_find(dev, prop_id);
+			prop = drm_mode_obj_find_prop_id(obj, prop_id);
 			if (!prop) {
 				drm_mode_object_unreference(obj);
 				ret = -ENOENT;

drivers/gpu/drm/drm_crtc_internal.h

@@ -115,6 +115,8 @@ int drm_mode_object_get_properties(struct drm_mode_object *obj, bool atomic,
 				   uint32_t __user *prop_ptr,
 				   uint64_t __user *prop_values,
 				   uint32_t *arg_count_props);
+struct drm_property *drm_mode_obj_find_prop_id(struct drm_mode_object *obj,
+					       uint32_t prop_id);
 
 /* IOCTL */
 

drivers/gpu/drm/drm_mode_object.c

@@ -372,14 +372,25 @@ out:
 	return ret;
 }
 
+struct drm_property *drm_mode_obj_find_prop_id(struct drm_mode_object *obj,
+					       uint32_t prop_id)
+{
+	int i;
+
+	for (i = 0; i < obj->properties->count; i++)
+		if (obj->properties->properties[i]->base.id == prop_id)
+			return obj->properties->properties[i];
+
+	return NULL;
+}
+
 int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
 				    struct drm_file *file_priv)
 {
 	struct drm_mode_obj_set_property *arg = data;
 	struct drm_mode_object *arg_obj;
-	struct drm_mode_object *prop_obj;
 	struct drm_property *property;
-	int i, ret = -EINVAL;
+	int ret = -EINVAL;
 	struct drm_mode_object *ref;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
@@ -392,23 +403,13 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data,
 		ret = -ENOENT;
 		goto out;
 	}
-	if (!arg_obj->properties)
-		goto out_unref;
-
-	for (i = 0; i < arg_obj->properties->count; i++)
-		if (arg_obj->properties->properties[i]->base.id == arg->prop_id)
-			break;
 
-	if (i == arg_obj->properties->count)
+	if (!arg_obj->properties)
 		goto out_unref;
 
-	prop_obj = drm_mode_object_find(dev, arg->prop_id,
-					DRM_MODE_OBJECT_PROPERTY);
-	if (!prop_obj) {
-		ret = -ENOENT;
+	property = drm_mode_obj_find_prop_id(arg_obj, arg->prop_id);
+	if (!property)
 		goto out_unref;
-	}
-	property = obj_to_property(prop_obj);
 
 	if (!drm_property_change_valid_get(property, arg->value, &ref))
 		goto out_unref;