Meelis and Helge reported that 3a9ad0b4 ("PCI: Add pci_bus_addr_t")
caused HPMCs on A500 and hangs on rp5470.

PA-RISC does not set ARCH_DMA_ADDR_T_64BIT, even for 64-bit kernels, so
prior to 3a9ad0b4, we always used 32-bit PCI addresses.  After
3a9ad0b4, we do use 64-bit PCI addresses in 64-bit kernels, and
apparently there's some PA-RISC problem related to them.

Fixes: 3a9ad0b4 ("PCI: Add pci_bus_addr_t")
Link: http://lkml.kernel.org/r/alpine.LRH.2.11.1507260929000.30065@math.ut.eeReported-by: Meelis Roos <mroos@linux.ee>
Reported-by: Helge Deller <deller@gmx.de>
Tested-by: Helge Deller <deller@gmx.de>
Based-on-idea-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
CC: stable@vger.kernel.org	# v3.19+