PCI update for v3.18:

  NVIDIA Tegra
    - Use physical range for I/O mapping (Thierry Reding)
PCI: tegra: Use physical range for I/O mapping

Commit 0b0b0893d49b ("of/pci: Fix the conversion of IO ranges into IO
resources") changed how I/O resources are parsed from DT.  Rather than
containing the physical address of the I/O region, the addresses will now
be in I/O address space.

On Tegra the union of all ranges is used to expose a top-level memory-
mapped resource for the PCI host bridge.  This helps to make /proc/iomem
more readable.

Combining both of the above, the union would now include the I/O space
region.  This causes a regression on Tegra20, where the physical base
address of the PCIe controller (and therefore of the union) is located at
physical address 0x80000000.  Since I/O space starts at 0, the union will
now include all of system RAM which starts at 0x00000000.

This commit fixes this by keeping two copies of the I/O range: one that
represents the range in the CPU's physical address space, the other for the
range in the I/O address space.  This allows the translation setup within
the driver to reuse the physical addresses.  The code registering the I/O
region with the PCI core uses both ranges to establish the mapping.

Fixes: 0b0b0893d49b ("of/pci: Fix the conversion of IO ranges into IO resources")
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
1 file changed