> On Monday 21 December 2015, Tomasz Nowicki wrote: >> On 21.12.2015 13:10, Lorenzo Pieralisi wrote: >> > On Fri, Dec 18, 2015 at 06:56:39PM +0000, okaya@xxxxxxxxxxxxxx wrote: > >> >> I have multiple root ports with the same IO port configuration in the >> >> current ACPI table. >> >> >> >> Root port 0 = IO range 0x1000-0x10FFF >> >> Root port 1 = IO range 0x1000-0x10FFF >> >> Root port 2 = IO range 0x1000-0x10FFF >> > >> > It is fine. You end up mapping for each of those a 4k window of the >> > virtual address space allocated to IO and that's what you will have in >> > the kernel PCI resources (not in the HW BARs though). If that was a >> problem >> > it would be even for the current DT host controllers eg: >> > >> > arch/arm64/boot/dts/apm/apm-storm.dtsi >> > >> > it should not be (again I will let Arnd comment on this since he may >> be >> > aware of issues encountered on other arches/platforms). >> > >> >> Root port 0 = IO range 0x1000-0x10FFF >> Root port 1 = IO range 0x1000-0x10FFF >> Root port 2 = IO range 0x1000-0x10FFF >> >> If above ranges are mapped into different CPU windows, then yes, it is >> fine. > > Ideally, they should all be the same CPU address so we only have to map > the window > once, each device gets an address below 64K, and you can have legacy port > numbers > (below 4K) on any bus, which is required to make certain GPUs work. > > I haven't actually seen anyone do that on ARM though, every implementation > so > far has a separate mapping per host bridge, and we can cope with that too, > and we can live with either overlapping bus addresses or unique bus > addresses, > any of them can be expressed by the PCI core in Linux, we just have to > make sure > that we correctly translate the firmware tables into our internal > structures. > > Arnd > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Thanks, I won't be touching the acpi tables then and I will assume the hack had a problem. It was trying to remap the io range of the second root port to the first port io address map. I was getting a warning from resource.c Btw, when I tested the io ranges before, kernel didn't accept anything below 1k like 0. That is why my range starts at 1k. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
