phrase → all You can say that's all at the end of a sentence when you are explaining something and want to emphasize that nothing more happens or is the case.
⇒ 'Why do you want to know that?' he demanded.—'Just curious, that's all.'
⇒ 'I had no desire to be a mother–I had a child, that's all.'
COBUILD Advanced English Dictionary. Copyright © HarperCollins Publishers