Add layer mask shortcut?

I realized that the "Reveal All" and "Reveal Selelction" options as shown in the screenshots are what we are looking for when we want to create a layer mask.
But reveal all will always give you a white layer mask, even if a selection is active, so there is a difference between these two, just in case anyone was wondering! 

and if you always want a black layer mask, that woudl be "Hide All"

Thanks!

Thank you, this is great if you want to add a White layer mask, but what about a keyboard shortcut to add a Black layer mask?

Hello, did you get a proper response to this question?
I too want a keyboard shorcut that does what the button at the bottom of the layer panel does. Reveal All or Reveal Selected depending if something is selected.

Just click on the add layer mask icon in the bottom of the layers palette. If you have an active selection it will be usea for the layer mask content. Otherwise a Show all or Hide all layer mask will be the layer mask added. The Alt key held down will invert the layer mask.  Not held down show all.  Held down inverted hide all.   I'm quite sure alt would also invert an active selection layer mask.