How do I memory map(mmap()) a region to user space as noncachable memory?

The problem appears to be that the system has mapped the memory range as cacheable and caching
needs to be disabled. I have written a device driver that exports a mmap() function that maps the
appropriate region as follows-

if (remap_page_range(vma->vm_start, offset, vma->vm_end - vma->vm_start, pgprot_noncached(vma->vm_page_prot)))
return -EAGAIN;


Any help would be greatly appreciated...