DMA

[shaig at shum.huji.ac.il]

I am currently preparing a device driver for a card that performs DMA to
addresses on a Sun4/60 S-bus. One of the limitations that I have
encountered is that the DMA memory area is limited to 600Kb, and the
memory buffers that my device would like to work with can reach 3*192Kb
each. Is it possible to reconfigure the kernel to a DMA size of say 900Kb?
If so how? If not, what is the cause of the actual limitation?