1 files changed, 152 insertions, 76 deletions

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 7a7019ac9388..45464c8b797d 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -23,6 +23,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_connector.h>
 #include <drm/drm_edid.h>
+#include <drm/drm_encoder.h>
 
 #include "drm_crtc_internal.h"
 #include "drm_internal.h"
@@ -37,18 +38,17 @@
  * Hence they are reference-counted using drm_connector_reference() and
  * drm_connector_unreference().
  *
- * KMS driver must create, initialize, register and attach at a struct
- * &drm_connector for each such sink. The instance is created as other KMS
- * objects and initialized by setting the following fields.
- *
- * The connector is then registered with a call to drm_connector_init() with a
- * pointer to the connector functions and a connector type, and exposed through
- * sysfs with a call to drm_connector_register().
+ * KMS driver must create, initialize, register and attach at a &struct
+ * drm_connector for each such sink. The instance is created as other KMS
+ * objects and initialized by setting the following fields. The connector is
+ * initialized with a call to drm_connector_init() with a pointer to the
+ * &struct drm_connector_funcs and a connector type, and then exposed to
+ * userspace with a call to drm_connector_register().
  *
  * Connectors must be attached to an encoder to be used. For devices that map
  * connectors to encoders 1:1, the connector should be attached at
  * initialization time with a call to drm_mode_connector_attach_encoder(). The
- * driver must also set the struct &drm_connector encoder field to point to the
+ * driver must also set the &drm_connector.encoder field to point to the
  * attached encoder.
  *
  * For connectors which are not fixed (like built-in panels) the driver needs to
@@ -189,13 +189,11 @@ int drm_connector_init(struct drm_device *dev,
 	struct ida *connector_ida =
 		&drm_connector_enum_list[connector_type].ida;
 
-	drm_modeset_lock_all(dev);
-
 	ret = drm_mode_object_get_reg(dev, &connector->base,
 				      DRM_MODE_OBJECT_CONNECTOR,
 				      false, drm_connector_free);
 	if (ret)
-		goto out_unlock;
+		return ret;
 
 	connector->base.properties = &connector->properties;
 	connector->dev = dev;
@@ -233,8 +231,10 @@ int drm_connector_init(struct drm_device *dev,
 
 	/* We should add connectors at the end to avoid upsetting the connector
 	 * index too much. */
+	spin_lock_irq(&config->connector_list_lock);
 	list_add_tail(&connector->head, &config->connector_list);
 	config->num_connector++;
+	spin_unlock_irq(&config->connector_list_lock);
 
 	if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL)
 		drm_object_attach_property(&connector->base,
@@ -259,9 +259,6 @@ out_put:
 	if (ret)
 		drm_mode_object_unregister(dev, &connector->base);
 
-out_unlock:
-	drm_modeset_unlock_all(dev);
-
 	return ret;
 }
 EXPORT_SYMBOL(drm_connector_init);
@@ -352,8 +349,10 @@ void drm_connector_cleanup(struct drm_connector *connector)
 	drm_mode_object_unregister(dev, &connector->base);
 	kfree(connector->name);
 	connector->name = NULL;
+	spin_lock_irq(&dev->mode_config.connector_list_lock);
 	list_del(&connector->head);
 	dev->mode_config.num_connector--;
+	spin_unlock_irq(&dev->mode_config.connector_list_lock);
 
 	WARN_ON(connector->state && !connector->funcs->atomic_destroy_state);
 	if (connector->state && connector->funcs->atomic_destroy_state)
@@ -444,30 +443,30 @@ EXPORT_SYMBOL(drm_connector_unregister);
 void drm_connector_unregister_all(struct drm_device *dev)
 {
 	struct drm_connector *connector;
+	struct drm_connector_list_iter conn_iter;
 
-	/* FIXME: taking the mode config mutex ends up in a clash with sysfs */
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
+	drm_connector_list_iter_get(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter)
 		drm_connector_unregister(connector);
+	drm_connector_list_iter_put(&conn_iter);
 }
 
 int drm_connector_register_all(struct drm_device *dev)
 {
 	struct drm_connector *connector;
-	int ret;
+	struct drm_connector_list_iter conn_iter;
+	int ret = 0;
 
-	/* FIXME: taking the mode config mutex ends up in a clash with
-	 * fbcon/backlight registration */
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+	drm_connector_list_iter_get(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
 		ret = drm_connector_register(connector);
 		if (ret)
-			goto err;
+			break;
 	}
+	drm_connector_list_iter_put(&conn_iter);
 
-	return 0;
-
-err:
-	mutex_unlock(&dev->mode_config.mutex);
-	drm_connector_unregister_all(dev);
+	if (ret)
+		drm_connector_unregister_all(dev);
 	return ret;
 }
 
@@ -489,6 +488,87 @@ const char *drm_get_connector_status_name(enum drm_connector_status status)
 }
 EXPORT_SYMBOL(drm_get_connector_status_name);
 
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map connector_list_iter_dep_map = {
+	.name = "drm_connector_list_iter"
+};
+#endif
+
+/**
+ * drm_connector_list_iter_get - initialize a connector_list iterator
+ * @dev: DRM device
+ * @iter: connector_list iterator
+ *
+ * Sets @iter up to walk the &drm_mode_config.connector_list of @dev. @iter
+ * must always be cleaned up again by calling drm_connector_list_iter_put().
+ * Iteration itself happens using drm_connector_list_iter_next() or
+ * drm_for_each_connector_iter().
+ */
+void drm_connector_list_iter_get(struct drm_device *dev,
+				 struct drm_connector_list_iter *iter)
+{
+	iter->dev = dev;
+	iter->conn = NULL;
+	lock_acquire_shared_recursive(&connector_list_iter_dep_map, 0, 1, NULL, _RET_IP_);
+}
+EXPORT_SYMBOL(drm_connector_list_iter_get);
+
+/**
+ * drm_connector_list_iter_next - return next connector
+ * @iter: connectr_list iterator
+ *
+ * Returns the next connector for @iter, or NULL when the list walk has
+ * completed.
+ */
+struct drm_connector *
+drm_connector_list_iter_next(struct drm_connector_list_iter *iter)
+{
+	struct drm_connector *old_conn = iter->conn;
+	struct drm_mode_config *config = &iter->dev->mode_config;
+	struct list_head *lhead;
+	unsigned long flags;
+
+	spin_lock_irqsave(&config->connector_list_lock, flags);
+	lhead = old_conn ? &old_conn->head : &config->connector_list;
+
+	do {
+		if (lhead->next == &config->connector_list) {
+			iter->conn = NULL;
+			break;
+		}
+
+		lhead = lhead->next;
+		iter->conn = list_entry(lhead, struct drm_connector, head);
+
+		/* loop until it's not a zombie connector */
+	} while (!kref_get_unless_zero(&iter->conn->base.refcount));
+	spin_unlock_irqrestore(&config->connector_list_lock, flags);
+
+	if (old_conn)
+		drm_connector_unreference(old_conn);
+
+	return iter->conn;
+}
+EXPORT_SYMBOL(drm_connector_list_iter_next);
+
+/**
+ * drm_connector_list_iter_put - tear down a connector_list iterator
+ * @iter: connector_list iterator
+ *
+ * Tears down @iter and releases any resources (like &drm_connector references)
+ * acquired while walking the list. This must always be called, both when the
+ * iteration completes fully or when it was aborted without walking the entire
+ * list.
+ */
+void drm_connector_list_iter_put(struct drm_connector_list_iter *iter)
+{
+	iter->dev = NULL;
+	if (iter->conn)
+		drm_connector_unreference(iter->conn);
+	lock_release(&connector_list_iter_dep_map, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(drm_connector_list_iter_put);
+
 static const struct drm_prop_enum_list drm_subpixel_enum_list[] = {
 	{ SubPixelUnknown, "Unknown" },
 	{ SubPixelHorizontalRGB, "Horizontal RGB" },
@@ -618,8 +698,8 @@ DRM_ENUM_NAME_FN(drm_get_tv_subconnector_name,
  * 	drivers this is only provided for backwards compatibility with existing
  * 	drivers, it remaps to controlling the "ACTIVE" property on the CRTC the
  * 	connector is linked to. Drivers should never set this property directly,
- * 	it is handled by the DRM core by calling the ->dpms() callback in
- * 	&drm_connector_funcs. Atomic drivers should implement this hook using
+ * 	it is handled by the DRM core by calling the &drm_connector_funcs.dpms
+ * 	callback. Atomic drivers should implement this hook using
  * 	drm_atomic_helper_connector_dpms(). This is the only property standard
  * 	connector property that userspace can change.
  * PATH:
@@ -1085,43 +1165,65 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 
 	memset(&u_mode, 0, sizeof(struct drm_mode_modeinfo));
 
-	mutex_lock(&dev->mode_config.mutex);
-
 	connector = drm_connector_lookup(dev, out_resp->connector_id);
-	if (!connector) {
-		ret = -ENOENT;
-		goto out_unlock;
-	}
+	if (!connector)
+		return -ENOENT;
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	encoder = drm_connector_get_encoder(connector);
+	if (encoder)
+		out_resp->encoder_id = encoder->base.id;
+	else
+		out_resp->encoder_id = 0;
+
+	ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
+			(uint32_t __user *)(unsigned long)(out_resp->props_ptr),
+			(uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
+			&out_resp->count_props);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+	if (ret)
+		goto out_unref;
 
 	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
 		if (connector->encoder_ids[i] != 0)
 			encoders_count++;
 
+	if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
+		copied = 0;
+		encoder_ptr = (uint32_t __user *)(unsigned long)(out_resp->encoders_ptr);
+		for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
+			if (connector->encoder_ids[i] != 0) {
+				if (put_user(connector->encoder_ids[i],
+					     encoder_ptr + copied)) {
+					ret = -EFAULT;
+					goto out_unref;
+				}
+				copied++;
+			}
+		}
+	}
+	out_resp->count_encoders = encoders_count;
+
+	out_resp->connector_id = connector->base.id;
+	out_resp->connector_type = connector->connector_type;
+	out_resp->connector_type_id = connector->connector_type_id;
+
+	mutex_lock(&dev->mode_config.mutex);
 	if (out_resp->count_modes == 0) {
 		connector->funcs->fill_modes(connector,
 					     dev->mode_config.max_width,
 					     dev->mode_config.max_height);
 	}
 
-	/* delayed so we get modes regardless of pre-fill_modes state */
-	list_for_each_entry(mode, &connector->modes, head)
-		if (drm_mode_expose_to_userspace(mode, file_priv))
-			mode_count++;
-
-	out_resp->connector_id = connector->base.id;
-	out_resp->connector_type = connector->connector_type;
-	out_resp->connector_type_id = connector->connector_type_id;
 	out_resp->mm_width = connector->display_info.width_mm;
 	out_resp->mm_height = connector->display_info.height_mm;
 	out_resp->subpixel = connector->display_info.subpixel_order;
 	out_resp->connection = connector->status;
 
-	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
-	encoder = drm_connector_get_encoder(connector);
-	if (encoder)
-		out_resp->encoder_id = encoder->base.id;
-	else
-		out_resp->encoder_id = 0;
+	/* delayed so we get modes regardless of pre-fill_modes state */
+	list_for_each_entry(mode, &connector->modes, head)
+		if (drm_mode_expose_to_userspace(mode, file_priv))
+			mode_count++;
 
 	/*
 	 * This ioctl is called twice, once to determine how much space is
@@ -1144,36 +1246,10 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 		}
 	}
 	out_resp->count_modes = mode_count;
-
-	ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
-			(uint32_t __user *)(unsigned long)(out_resp->props_ptr),
-			(uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
-			&out_resp->count_props);
-	if (ret)
-		goto out;
-
-	if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
-		copied = 0;
-		encoder_ptr = (uint32_t __user *)(unsigned long)(out_resp->encoders_ptr);
-		for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
-			if (connector->encoder_ids[i] != 0) {
-				if (put_user(connector->encoder_ids[i],
-					     encoder_ptr + copied)) {
-					ret = -EFAULT;
-					goto out;
-				}
-				copied++;
-			}
-		}
-	}
-	out_resp->count_encoders = encoders_count;
-
 out:
-	drm_modeset_unlock(&dev->mode_config.connection_mutex);
-
-	drm_connector_unreference(connector);
-out_unlock:
 	mutex_unlock(&dev->mode_config.mutex);
+out_unref:
+	drm_connector_unreference(connector);
 
 	return ret;
 }