On Fri, Feb 1, 2013 at 9:13 AM, Jiang Liu <liuj97@xxxxxxxxx> wrote: > 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? That seems fine to me. I think you wrote "pcibios_remove_bus(b)" below in pci_create_root_bus() when you probably meant "pcibios_add_bus(b)." But I'm sure you would have found that soon :) Anyway, I think a directly-called weak function will be much easier to understand than a notifier-based solution. Bjorn > 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-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
