On Fri, Jun 14, 2019 at 10:02:52AM +0100, John Garry wrote: > On 13/06/2019 21:09, Bjorn Helgaas wrote: > > On Thu, Jun 13, 2019 at 10:39:12AM +0100, John Garry wrote: > > > On 13/06/2019 03:39, Bjorn Helgaas wrote: > > > > I'm not sure it's even safe, because CONFIG_INDIRECT_PIO depends on > > > > ARM64, but PCI_IOBASE is defined on most arches via asm-generic/io.h, > > > > so this potentially affects arches other than ARM64. > > > > > > It would do. It would affect any arch which defines PCI_IOBASE and > > > does not have arch-specific definition of inb et all. > > > What's the reason for testing PCI_IOBASE instead of > > CONFIG_INDIRECT_PIO? If there's a reason it's needed, that's fine, > > but it does make this much more complicated to review. > > For ARM64, we have PCI_IOBASE defined but may not have > CONFIG_INDIRECT_PIO defined. Currently CONFIG_INDIRECT_PIO is only > selected by CONFIG_HISILICON_LPC. > > As such, we should make this change also for when > CONFIG_INDIRECT_PIO is not defined. OK. This is all very important for the commit log -- we need to understand what arches are affected and the reason they need it. Since the goal of this series is to fix an ARM64-specific issue, and the typical port I/O model is for each arch to #define its own inb(), maybe it would make sense to move the "#define inb logic_inb" from linux/logic_pio.h to arm64/include/asm/io.h? The "#ifndef inb" arrangement gets pretty complicated when it occurs more than one place (asm-generic/io.h and logic_pio.h) and we have to start worrying about the ordering of #includes. Bjorn
