Pierre Morel
05bc1be6db
s390/pci: create zPCI bus
The zPCI bus is in charge to handle common zPCI resources for zPCI devices. Creating the zPCI bus, the PCI bus, the zPCI devices and the PCI devices and hotplug slots done in a specific order: - PCI hotplug slot creation needs a PCI bus - PCI bus needs a PCI domain which is reported by the pci_domain_nr() when setting up the host bridge - PCI domain is set from the zPCI with devfn 0 this is necessary to have a reproducible enumeration Therefore we can not create devices or hotplug slots for any PCI device associated with a zPCI device before having discovered the function zero of the bus. The discovery and initialization of devices can be done at several points in the code: - On Events, serialized in a thread context - On initialization, in the kernel init thread context - When powering on the hotplug slot, in a user thread context The removal of devices and their parent bus may also be done on events or for devices when powering down the slot. To guarantee the existence of the bus and devices until they are no more needed we use kref in zPCI bus and introduce a reference count in the zPCI devices. In this patch the zPCI bus still only accept a device with a devfn 0. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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