In addition to the patches from http://00f.net/blogs/index.php/2004/...linux_2_6_9_mm
I've changed NV_REMAP_PAGE_RANGE to NV_REMAP_PFN_RANGE and remap_page_range to remap_pfn_range in nv-linux.h, nv.c, os-agp.c, and os-interface.c, the missing piece -- see below. I may get around to posting patches to the nvidia forum later today.
I'm not sure if I can divulge the name of my helper in case he gets showered by unwanted email, but a suggested additional change to nv-linux.h has fixed it.
#define NV_REMAP_PFN_RANGE(from, offset, x...) \
remap_pfn_range(vma, from, ((offset)) >> PAGE_SHIFT), x)