Quoting r. Ian Pratt <m+Ian.Pratt@xxxxxxxxxxxx>:
> Subject: RE: [Xen-devel] Userspace PIO access under xen
> > You can also use /proc/bus/pci/ for this, the difference is
> > that you have to give full bus address to /proc/bus/pci/ ,
> > while /sys/bus/pci/devices/ needs an offset within the resource.
> > > Change pci_mmap_page_range in arch/xen/arch/pci/i386.c to use
> > > io_remap_pfn_range
> > I've written a small kernel module to map PIO to userspace
> > using remap_page_range, and that doesnt seem to work, either.
> You have to use io_remap_pfn_range for mapping IO space. Using
> remap_pfn_range is technically a bug in the i386 code.
#define io_remap_page_range(vma, vaddr, paddr, size, prot) \
remap_pfn_range(vma, vaddr, (paddr) >> PAGE_SHIFT, size, prot)
So I just tested again and of course io_remap_pfn_range gives the same result.
> I believe the pfn_range functions are preferred over page_range
> functions anyhow.
I actually use remap_pfn_range, I mistyped that.
Point is, none of these works.
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