On Mon, Sep 29, 2014 at 3:02 PM, Benjamin Herrenschmidt <b...@kernel.crashing.org> wrote: > On Mon, 2014-09-29 at 12:06 -0700, Yinghai Lu wrote: >> On Mon, Sep 29, 2014 at 11:25 AM, Yinghai Lu <ying...@kernel.org> wrote: >> > On Mon, Sep 29, 2014 at 7:29 AM, Liviu Dudau <liviu.du...@arm.com> wrote: >> >> If the firmware has not assigned all the bus resources and we are not just >> >> probing the PCI buses, it makes sense to assign the unassigned resources >> >> in pci_scan_root_bus(). >> >> >> >> Signed-off-by: Liviu Dudau <liviu.du...@arm.com> >> >> Signed-off-by: Bjorn Helgaas <bhelg...@google.com> >> >> CC: Arnd Bergmann <a...@arndb.de> >> >> CC: Jason Gunthorpe <jguntho...@obsidianresearch.com> >> >> CC: Rob Herring <robh...@kernel.org> >> >> --- >> >> drivers/pci/probe.c | 3 +++ >> >> 1 file changed, 3 insertions(+) >> >> >> >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c >> >> index 636d1c9..d2ebd49 100644 >> >> --- a/drivers/pci/probe.c >> >> +++ b/drivers/pci/probe.c >> >> @@ -1951,6 +1951,9 @@ struct pci_bus *pci_scan_root_bus(struct device >> >> *parent, int bus, >> >> if (!found) >> >> pci_bus_update_busn_res_end(b, max); >> >> >> >> + if (!pci_has_flag(PCI_PROBE_ONLY)) >> >> + pci_assign_unassigned_bus_resources(b); >> >> + >> >> pci_bus_add_devices(b); >> >> return b; >> >> } >> > >> > No, you can not do it that early. >> > >> > On x86, we need to call >> > pcibios_resource_survey_bus at first. >> >> on x86: >> pcibios_init >> pcibios_resource_survey() >> pcibios_assign_resources() via fs_initcall > > Right and on powerpc and others as well. We need to survey existing > resources. We also have a number of platform things that might need > to happen before we do the final re-assignment pass.
That's true today. But I don't know whether it *has* to be this way forever. On x86, pcibios_resource_survey() throws in E820 information (which we know long before we do any PCI enumeration) and some IO-APIC resources (it looks like we also know these before PCI enumeration). Powerpc has pcibios_reserve_legacy_regions(), but that looks like mostly stuff that could be done when we find the host bridge, before we enumerate PCI devices below it. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
