On Friday 02 January 2015 12:18:06 Suravee Suthikulanit wrote: > On 1/2/2015 5:55 AM, Lorenzo Pieralisi wrote: > > Hi Suravee, > > > > On Mon, Dec 29, 2014 at 07:32:44PM +0000, Suravee Suthikulpanit wrote: > >> >Hi, > >> > > >> >I am not sure if this thread is still alive. I'm trying to see what I > >> >can do to help clean up/convert to make the PCI GHC also works for arm64 > >> >w/ zero or minimal ifdefs. > >> > > >> >Please let me know if someone is already working on this. I noticed that > >> >Lorenzo's patches has already been in 3.19-rc1, and in Bjorn's > >> >pci/domain branch. Otherwise, I'll try to continue the work based on the > >> >sample patch from Arnd here. > > If I am not mistaken, the only bit missing to remove pci_sys_data (and so > > having a generic host controller driver that works on ARM32/64) is generic > > MSI management. > > Lorenzo, > > Do you mean to remove pci_sys_data from pci-host-generic.c or removing > it completely? I assume the former case. Something inbetween: We should be able to remove pci_sys_data and pci_common_init_dev from all drivers in drivers/pci/host/, but keep them for all drivers in arch/arm/*/pci.c > So, looking at the current code in the pci-host-generic.c, my > understanding is that the: > *gen_pci = pci_bus->sysdata->private_data > will be changed to: > *gen_pci = pci_bus->sysdata > > Then, we can simply just call pci_scan_root_bus() directly since we no > longer need to declare hw_pci for calling pci_common_init_dev(). Right. > > I know for certain Marc is working on it, and the solution is WIP, > > I think we should prevent adding more churn to pci_sys_data, since > > I managed to remove most of the dependencies (domain, mem_offset). > > Thanks for cleaning up the domain and mem_offset. > > I saw Marc's irq/msi_domain patch series > (http://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/log/?h=irq/msi_domain). > > > My understanding is that deals with associating the newly introduced > msi_domain to each device, which replaces the need for pci_bus->msi and > hw_pci->msi_ctrl when configure with CONFIG_PCI_MSI_IRQ_DOMAIN (not sure > if this would be the plan for all arm32). For ARM32, if not define > CONFIG_PCI_MSI_IRQ_DOMAIN, it would still fall back to using the > [pci_sys_data|hw_pci]->msi_ctrl. For all I can tell, we have two cases on ARM regarding MSI: - arch/arm/mach-iop13xx/pci.c uses its own arch_setup_msi_irq/arch_teardown_msi_irq implementation and does not use pci_bus->msi. - everything else that supports MSI has a modern driver with multiplatform support and uses msi_controller. If any platform wants to support GICv2m, we have to use CONFIG_PCI_MSI_IRQ_DOMAIN for all of them, and that seems like the best way forward. 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
