On Wed, Jun 08, 2016 at 12:04:46PM +0100, Lorenzo Pieralisi wrote: > Current arm/arm64 code prevents enabling resources in the respective > pcibios_enable_device() callbacks if the PCI_PROBE_ONLY flag is set, > in that on those platforms the resources tree was not validated properly > since PCI resources are not currently claimed on arm/arm64 PCI_PROBE_ONLY > systems. > > This is a temporary kludge, in that PCI_PROBE_ONLY flag is used to > describe systems with fixed resources, that can nonetheless be enabled > through the standard pci_enable_resources() call present in PCI core code, > (ie via the generic pcibios_enable_device() call). > > To remove the PCI_PROBE_ONLY flag in arm/arm64 pcibios_enable_device() > callbacks, the PCI host controllers that can be used with > PCI_PROBE_ONLY configurations must make sure that devices resources are > validated and inserted in the kernel resource tree even on PCI_PROBE_ONLY > systems so that the generic pcibios_enable_device() generic code, while > enabling resources (pci_enable_resources()), does not find dangling > resources pointers (ie missing parent pointers) that are omens of > an incomplete resource tree, causing failures in resources enablement. > > PCI core code provides interfaces to assign/reassign/reallocate PCI > bus resources but it is currently lacking an interface to claim > resources for a specific bus. Arches implement resources claiming through > ad-hoc code built on top of pci_claim_resource() API, but that code > cannot be leveraged on architectures like arm/arm64 that rely on the > generic PCI infrastructure to carry out resources claiming/assignment. > > Therefore, to clean up the arm/arm64 resources enablement on > PCI_PROBE_ONLY systems this patchset implements four patches: > > PATCH 1: Create PCI core code infrastructure to claim bus resources > PATCH 2: Leverage the infrastructure in PATCH 1 to claim resources in > the PCI generic host controller on PCI_PROBE_ONLY systems > > PATCH 3: Remove the PCI_PROBE_ONLY kludge from the arm64 PCI back-end to > complete the clean-up and leverage the PCI generic > pcibios_enable_device() implementation > > PATCH 4: Remove the PCI_PROBE_ONLY kludge from the arm PCI back-end to > complete the clean-up and leverage the PCI generic > pcibios_enable_device() implementation > > Tested on arm/arm64 systems with kvmtool and PCI host generic. > > v2 -> v3 > > - Split patch 3 in two patches so that arm and arm64 are handled > in different patches > - Improved commits logs, clarified resource parent assignment > - Rebased against v4.7-rc2 > > v2: https://patchwork.ozlabs.org/patch/590556/ > > v1 -> v2 > > - Rewrote patch 1 to recursively claim resources for the whole PCI bus > hierarchy > - Updated commits logs/tags > - Rebased against v4.5-rc6 > > v1: https://patchwork.ozlabs.org/patch/545669/ > > Lorenzo Pieralisi (4): > PCI: add generic code to claim bus resources > PCI: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups > ARM64/PCI: remove arch specific pcibios_enable_device() > ARM/PCI: remove arch specific pcibios_enable_device() > > arch/arm/kernel/bios32.c | 12 ------- > arch/arm64/kernel/pci.c | 13 -------- > drivers/pci/host/pci-host-common.c | 27 +++++++++++++-- > drivers/pci/setup-bus.c | 68 ++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 1 + > 5 files changed, 94 insertions(+), 27 deletions(-) I applied these to pci/resource for v4.8, thanks, Lorenzo! It's awesome to get rid of that PCI_PROBE_ONLY hack. We might still tweak this a little based on my question about pci_common_init_dev(), so don't build things on top of this yet (good advice in general for my branches: I often rebase and remerge them, so it's best to base things on my "master" branch unless you actually depend on something that's not in there.) -- 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
