bigmem in 2.2.17

Hi All,

I'm trying to write a driver for a PCI card and would like to use the
bigmem patch. My development system is running 2.2.17-21mdk (Mandrake 
7.2), but as soon as I make a call to kmap() I get unresolved symbols 
bigmem_start, kmap_prot and kmap_pte. They ARE in System.map, but not 
/proc/ksyms and, indeed, there doesn't seem to be any EXPORT_SYMBOL 
directive for them in kernel/ksyms.c. I'm guessing there's something else 
I need to do but don't know what. Any ideas??

Also, does GFP_BIGMEM give me physical contiguous pages, suitable for
DMA by a PCI card? I know of GFP_DMA, but wondered if that was really
intended for ISA cards.

TIA

Matt