Sources for info about firewire security

[Bruno Wolff III]

I am looking for places to read about protections taken in linux to prevent
firewire devices from dumping memory. This is a set up over other physical
access attacks because of the potential for grabbing memory contents without
having to reboot a machine. (Which could expose things such as keys for
encrypted partitions.)

I have found some sources describing that firewire devices can use bus
mastering to dma various regions of memory and that you can prevent this
by not loading firewire modules, but I haven't been able to frame a google
search to find discussion about whether protecting against this in the
drivers is possible and whether anything has been implented.