On 01/29/2013 10:04 AM, Jiang Liu wrote: > On 2013-1-29 8:34, Rafael J. Wysocki wrote: >> On Monday, January 28, 2013 01:56:33 PM Bjorn Helgaas wrote: >>> On Fri, Jan 18, 2013 at 9:07 AM, Jiang Liu <liuj97@xxxxxxxxx> wrote: >>>> This is an RFC patchset to address review comments in thread at: >>>> https://patchwork.kernel.org/patch/1946851/. The patch just pasts >>>> compilation. If no objection to the new implementation, I will >>>> go on to modify acpiphp driver and conduct tests. >>>> >>>> The main changes from V4 to V5 includes: >>>> 1) introduce a dedicated notifier chain for PCI buses >>>> 2) change pci_slot as built-in driver >>>> 3) unify the way to create/destroy PCI slots >>>> 4) introduce a kernel option to disable PCIe native hotplug >>>> >>>> TODO: >>>> 1) change acpiphp as built-in and unify the way to create/destroy ACPI >>>> based hotplug slots. >>>> 2) change other ACPI PCI subdriver in Yinghai's root bridge hotplug series >>>> to use the PCI bus notifier chain. >>>> 3) Remove the ACPI PCI subdriver interface eventaully. >>>> >>>> Jiang Liu (8): >>>> PCI: make PCI device create/destroy logic symmetric >>>> PCI: split registration of PCI bus devices into two stages >>>> PCI: add a blocking notifier chain for PCI bus addition/removal >>>> ACPI, PCI: avoid building pci_slot as module >>>> PCI, ACPI: hook PCI bus notifications to create/destroy PCI slots >>>> pci_slot: replace printk(KERN_xxx) with pr_xxx() >>>> PCI/PCIe: add "pci=nopciehp" to disable PCIe native hotplug >>>> PCI/PCIe: only claim PME from firmware when CONFIG_PCIE_PME is >>>> enabled >>>> >>>> Documentation/kernel-parameters.txt | 2 + >>>> drivers/acpi/Kconfig | 5 +- >>>> drivers/acpi/internal.h | 5 + >>>> drivers/acpi/pci_root.c | 8 +- >>>> drivers/acpi/pci_slot.c | 217 ++++++++++------------------------- >>>> drivers/acpi/scan.c | 1 + >>>> drivers/pci/bus.c | 26 ++++- >>>> drivers/pci/pci.c | 2 + >>>> drivers/pci/pci.h | 1 + >>>> drivers/pci/pcie/portdrv_core.c | 7 +- >>>> drivers/pci/pcie/portdrv_pci.c | 3 + >>>> drivers/pci/probe.c | 7 +- >>>> drivers/pci/remove.c | 15 +-- >>>> include/linux/pci.h | 21 ++++ >>>> 14 files changed, 142 insertions(+), 178 deletions(-) >>> >>> I think the problem we're trying to solve is that we don't initialize >>> hot-added devices, correctly, e.g., we don't set up AER, we don't >>> update acpi/pci_slot stuff, we probably don't set up PME etc. We also >>> have similar issues like IOMMU init on powerpc. >>> >>> Notifier chains seem like an unnecessarily complicated way to deal >>> with this. They're great for communicating between modules that stay >>> at arm's length from each other. But that's not the case here -- >>> everything is PCI and is quite closely coupled. I think AER, PME, >>> slot, etc., should be initialized directly in pci_device_add() or >>> somewhere nearby. >> >> I agree. >> >>> This might sound a bit radical because it implies some fairly >>> far-reaching changes. It means this code can't be a module (the only >>> one that can be built as a module today is pciehp, and I think >>> everybody agrees that we should make it static as soon as we can >>> figure out the acpiphp/pciehp issue). I think it also means the >>> pcieportdrv concept is of dubious value, since all the services should >>> be known at build-time and we probably don't need a registration >>> interface for them. >> >> It is of dubious value regardless. It just adds complexity for no gain. >> Moreover, these things are in fact not mutually independent. >> >> I've had a lot of headaches trying to work around that when I was working >> on PME support and later on _OSC for root bridges. Let's just take that >> stuff away once and for good. :-) > Hi Bjorn and Rafael, > Thanks for advice. We will go this direction to change those modules > as built-in. > Regards! > Gerry > Hi Bjorn, I have done some investigation about how to implement this without using notifier chain. Due to commit "PCI: Put pci_dev in device tree as early as possible", a PCI device will be registered to the driver core before creating the subordinate PCI bus. So we can't reply on the ACPI PCI device glue code to create/destroy PCI slots or acpiphp hotplug slots. So my current plan is to introduce two weak functions as below, is it acceptable? Regards! Gerry diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b494066..a5c22e7 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -673,6 +673,8 @@ add_dev: ret = device_register(&child->dev); WARN_ON(ret < 0); + pcibios_add_bus(child); + /* Create legacy_io and legacy_mem files for this bus */ pci_create_legacy_files(child); @@ -1661,6 +1663,14 @@ int __weak pcibios_root_bridge_prepare(struct pci_host_bridge * return 0; } +void __weak pcibios_add_bus(struct pci_bus *bus) +{ +} + +void __weak pcibios_remove_bus(struct pci_bus *bus) +{ +} + struct pci_bus *pci_create_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources) { @@ -1715,6 +1725,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int b if (error) goto class_dev_reg_err; + pcibios_remove_bus(b); + /* Create legacy_io and legacy_mem files for this bus */ pci_create_legacy_files(b); diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index fc38c48..3dbdf82 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -52,6 +52,7 @@ void pci_remove_bus(struct pci_bus *bus) return; pci_remove_legacy_files(bus); + pcibios_remove_bus(child); device_unregister(&bus->dev); } EXPORT_SYMBOL(pci_remove_bus); diff --git a/include/linux/pci.h b/include/linux/pci.h index 056d3d6..fd8ba0c 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -380,6 +380,8 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge, void *release_data); int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge); +void pcibios_add_bus(struct pci_bus *bus); +void pcibios_remove_bus(struct pci_bus *bus); /* * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond >> >> Thanks, >> Rafael >> >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
