How do I make linuxcnc aware of hard limits?

Hello, 
I have a teach in lathe that has a switch on the cross slide that is actuated when its about to enter in collision with the tailstock. So if the tailstock is moved forward for drilling a hole or smth, if I go too close to the tailstock, it will press switch, that in the old siemens control, it was cutting the power to the drives (actually disconnecting the motor from the drives).
Now I have new Delta ASDA A2 drives, that can take that input and inhibit the motion towards Z+, but how do I tell linuxcnc what happened? And how should I back it off from that limit. In case of the Z axis, its simple, I can just move the tailstock away, but for X+- hard limits (that I can reach if I jog the machine when not homed), they are not accessible and I cannot unpress the switches that easily. 
I am wondering how should I handle this scenario in linuxcnc so that I can jog back from a hard limit.
Thanks!

If you just tie into the standard limit switches, most (all?) the screens allow you to override the limits to jog away.