bin/magento dev:urn-catalog:generate -- .idea/misc.xml
make sure your path to the magento2 installation in phpstorm is the same, or update the paths in the misc.xml file.
+ restart phpstorm
Tag: phpstorm
PhpStorm: Inotify Watches Limit
http://confluence.jetbrains.com/display/IDEADEV/Inotify+Watches+Limit
gives an issue, add the following file: