Is there a way to either create a page table and/or map PCI memory to pages?

Also what does ioremap_page and ioremap_page_range do?

After ioremap is called, the PCI BAR memory is inserted into page table.

So I've tried doing a virt_to_page on the address returned from ioremap but it looks like it is returning a page for physical address that does not match the physical address I originally passed into ioremap. For example I pass ioremap 0x3C000000 and it returns 0x78400000. Then if I do a virt_to_page on 0x78400000 it returns a page for 0x38400000 not 0x3C000000. Should I not use virt_to_page for an ioremap virtual address? Is there some other function I should be using, i.e. ioremap_to_page, or something like that?

This is all on a PowerPC system.

virt_to_page return a pointer to page structure, not physical address.

Yes I under stand that, but that page is mapped to a physical address, i.e. page_to_phys, and the page that is returned is mapped to the physical address 0x38400000 not 0x3C000000. Also is I do a virt_to_phys on the virtual address from ioremap that also returns 0x38400000 and not 0x3C000000.

Do you have a machine with IOMMU? If so, it is possible because you have bus addresses that may be different than physical ones.

It looks like all IOMMU stuff is disabled in the kernel.

You can try pci_map_page after doing virt_to_page.