5db66334a7
To support IOAPIC hotplug on x86 and IA64 platforms, OS needs to figure out global interrupt source number(GSI) and IOAPIC enumeration ID through ACPI interfaces. So BIOS must implement an ACPI IOAPIC device with _GSB/_UID or _MAT method to support IOAPIC hotplug. OS also needs to figure out base physical address to access IOAPIC registers. OS may get the base physical address through PCI BARs if IOAPIC device is visible in PCI domain, otherwise OS may get the address by ACPI _CRS method if IOAPIC device is hidden from PCI domain by BIOS. When adding a PCI subtree, we need to add IOAPIC devices before enabling all other PCI devices because other PCI devices may use the IOAPIC to allocate PCI interrupts. So we plan to reimplement IOAPIC driver as an ACPI instead of PCI driver due to: 1) hot-pluggable IOAPIC devices are always visible in ACPI domain, but may or may not be visible in PCI domain. 2) we could explicitly control the order between IOAPIC and other PCI devices. We also have another choice to use a PCI driver to manage IOAPIC device if it's visible in PCI domain and use an ACPI driver if it's only visible in ACPI domain. But this solution is a little complex. It shouldn't cause serious backward compatibility issues because: 1) IOAPIC hotplug is never supported on x86 yet because it hasn't implemented the required acpi_register_ioapic() and acpi_unregister_ioapic(). 2) Currently only ACPI based IOAPIC hotplug is possible on x86 and IA64, we don't know other specifications and interfaces to support IOAPIC hotplug yet. 3) We will reimplement an ACPI IOAPIC driver to support IOAPIC hotplug. This change also helps to get rid of the false alarm on all current Linux distributions: [ 6.952497] ioapic: probe of 0000:00:05.4 failed with error -22 [ 6.959542] ioapic: probe of 0000:80:05.4 failed with error -22 Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1414387308-27148-9-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
118 lines
3.2 KiB
Plaintext
118 lines
3.2 KiB
Plaintext
#
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# PCI configuration
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#
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config PCI_MSI
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bool "Message Signaled Interrupts (MSI and MSI-X)"
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depends on PCI
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select GENERIC_MSI_IRQ
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help
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This allows device drivers to enable MSI (Message Signaled
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Interrupts). Message Signaled Interrupts enable a device to
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generate an interrupt using an inbound Memory Write on its
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PCI bus instead of asserting a device IRQ pin.
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Use of PCI MSI interrupts can be disabled at kernel boot time
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by using the 'pci=nomsi' option. This disables MSI for the
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entire system.
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If you don't know what to do here, say Y.
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config PCI_MSI_IRQ_DOMAIN
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bool
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depends on PCI_MSI
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select GENERIC_MSI_IRQ_DOMAIN
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config PCI_DEBUG
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bool "PCI Debugging"
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depends on PCI && DEBUG_KERNEL
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help
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Say Y here if you want the PCI core to produce a bunch of debug
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messages to the system log. Select this if you are having a
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problem with PCI support and want to see more of what is going on.
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When in doubt, say N.
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config PCI_REALLOC_ENABLE_AUTO
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bool "Enable PCI resource re-allocation detection"
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depends on PCI
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help
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Say Y here if you want the PCI core to detect if PCI resource
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re-allocation needs to be enabled. You can always use pci=realloc=on
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or pci=realloc=off to override it. Note this feature is a no-op
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unless PCI_IOV support is also enabled; in that case it will
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automatically re-allocate PCI resources if SR-IOV BARs have not
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been allocated by the BIOS.
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When in doubt, say N.
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config PCI_STUB
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tristate "PCI Stub driver"
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depends on PCI
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help
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Say Y or M here if you want be able to reserve a PCI device
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when it is going to be assigned to a guest operating system.
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When in doubt, say N.
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config XEN_PCIDEV_FRONTEND
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tristate "Xen PCI Frontend"
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depends on PCI && X86 && XEN
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select PCI_XEN
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select XEN_XENBUS_FRONTEND
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default y
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help
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The PCI device frontend driver allows the kernel to import arbitrary
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PCI devices from a PCI backend to support PCI driver domains.
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config HT_IRQ
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bool "Interrupts on hypertransport devices"
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default y
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depends on PCI && X86_LOCAL_APIC && X86_IO_APIC
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help
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This allows native hypertransport devices to use interrupts.
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If unsure say Y.
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config PCI_ATS
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bool
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config PCI_IOV
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bool "PCI IOV support"
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depends on PCI
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select PCI_ATS
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help
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I/O Virtualization is a PCI feature supported by some devices
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which allows them to create virtual devices which share their
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physical resources.
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If unsure, say N.
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config PCI_PRI
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bool "PCI PRI support"
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depends on PCI
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select PCI_ATS
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help
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PRI is the PCI Page Request Interface. It allows PCI devices that are
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behind an IOMMU to recover from page faults.
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If unsure, say N.
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config PCI_PASID
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bool "PCI PASID support"
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depends on PCI
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select PCI_ATS
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help
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Process Address Space Identifiers (PASIDs) can be used by PCI devices
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to access more than one IO address space at the same time. To make
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use of this feature an IOMMU is required which also supports PASIDs.
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Select this option if you have such an IOMMU and want to compile the
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driver for it into your kernel.
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If unsure, say N.
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config PCI_LABEL
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def_bool y if (DMI || ACPI)
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select NLS
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source "drivers/pci/host/Kconfig"
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