am i eligible for the 144-hour visa-exemption transit policy?

We are leaving in the Majestic Princess cruise on March 11, 2018, from Singapore (14-day cruise) and arriving Shanghai on March 25 at 7:00am. We are staying in Shanghai (touring on our own) from March 25 to March 28 (3 days). We are leaving Shanghai on March 28 at 1210 pm back to the United States. The ports we will visit in order are: Singapore, Bangkok, Ho Chi Minh City, Hong Kong, Busan, Nagasaki, Shanghai). Do we need to do anything in advance for our stay in Shanghai? Do we need to fill out a D/E card in advance?
Thanks!
Lee Gonzales