On Fri, Jan 02, 2015 at 09:09:33PM +0000, Arnd Bergmann wrote: > 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. Yes, I think that's the current situation. With a hook (added by Marc's code) in PCI core to set the msi domain (DT), all we need to do is convert the generic host controller code to pci_scan_root_bus() and remove the pcibios init calls, it is a mechanical change when all patches mentioned above are merged. Thanks, Lorenzo -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
