To China with a few friends, the embassy only gave me one entry

Arrive Monday in Hong Kong, Friday to Macau, leave Macau Saturday for Chengdu. Stay in Chengdu from Saturday until Friday. Then Friday go to Shanghai till Monday when we leave.

Am I correct in saying once I enter Chengdu that is my one entry into mainland China and I can go to Shanghai without a visa? Chengdu and Shanghai are considered mainland so only one entry needed???