FW: increasing the amount of memory that can be registered

Word of mouth is that it is possible to specify the amount of memory
that is available to be registered as a parameter. Can I increasing the
upper limit for the amount of memory gm can register by specifying it as
a parameter for the gm module? Could you tell me how to do that? I was
unable to find it in the documentation.

Also, how is the upper limit determined?

I was seeing in the documents somewhere that when same memory is
registered for 2 ports, gm realizes it and avoids duplication. Is it
true.

All my questions are in regards to gm2, we have e cards.

Thanks,
Vinod.