[PATCH]: MPSAFE isa_dma* functions for i386/amd64

hi

I have a patch that makes isa_dma* routines MPSAFE on i386/amd64.
These routines are also present in ia64/sparc64. Sparc64 provides just
empty stubs and ia64 should be removed (according to Marcel Moolenaar).

there are some old drivers that use this - most prominently ppc(4) and fdc(4)

if you have this hardware please test the attached patch or you can download
it here:

	http://www.vlakno.cz/~rdivacky/isa_dma-locking.patch

the patch was reviewed by jhb_at_ but never tested on a real hw (as I have none).
most of the users of the isa_dma* routines are still covered by Giant because
they are used in drivers attach routines (which are Giant locked) but ppc/fdc
use those in the normal code as well

thank you very much for testing

	roman