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diff --git a/Documentation/s390/pci.rst b/Documentation/s390/pci.rst deleted file mode 100644 index 492850bff316..000000000000 --- a/Documentation/s390/pci.rst +++ /dev/null @@ -1,125 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -========= -S/390 PCI -========= - -Authors: - - Pierre Morel - -Copyright, IBM Corp. 2020 - - -Command line parameters and debugfs entries -=========================================== - -Command line parameters ------------------------ - -* nomio - - Do not use PCI Mapped I/O (MIO) instructions. - -* norid - - Ignore the RID field and force use of one PCI domain per PCI function. - -debugfs entries ---------------- - -The S/390 debug feature (s390dbf) generates views to hold various debug results in sysfs directories of the form: - - * /sys/kernel/debug/s390dbf/pci_*/ - -For example: - - - /sys/kernel/debug/s390dbf/pci_msg/sprintf - Holds messages from the processing of PCI events, like machine check handling - and setting of global functionality, like UID checking. - - Change the level of logging to be more or less verbose by piping - a number between 0 and 6 to /sys/kernel/debug/s390dbf/pci_*/level. For - details, see the documentation on the S/390 debug feature at - Documentation/s390/s390dbf.rst. - -Sysfs entries -============= - -Entries specific to zPCI functions and entries that hold zPCI information. - -* /sys/bus/pci/slots/XXXXXXXX - - The slot entries are set up using the function identifier (FID) of the - PCI function. - - - /sys/bus/pci/slots/XXXXXXXX/power - - A physical function that currently supports a virtual function cannot be - powered off until all virtual functions are removed with: - echo 0 > /sys/bus/pci/devices/XXXX:XX:XX.X/sriov_numvf - -* /sys/bus/pci/devices/XXXX:XX:XX.X/ - - - function_id - A zPCI function identifier that uniquely identifies the function in the Z server. - - - function_handle - Low-level identifier used for a configured PCI function. - It might be useful for debuging. - - - pchid - Model-dependent location of the I/O adapter. - - - pfgid - PCI function group ID, functions that share identical functionality - use a common identifier. - A PCI group defines interrupts, IOMMU, IOTLB, and DMA specifics. - - - vfn - The virtual function number, from 1 to N for virtual functions, - 0 for physical functions. - - - pft - The PCI function type - - - port - The port corresponds to the physical port the function is attached to. - It also gives an indication of the physical function a virtual function - is attached to. - - - uid - The unique identifier (UID) is defined when configuring an LPAR and is - unique in the LPAR. - - - pfip/segmentX - The segments determine the isolation of a function. - They correspond to the physical path to the function. - The more the segments are different, the more the functions are isolated. - -Enumeration and hotplug -======================= - -The PCI address consists of four parts: domain, bus, device and function, -and is of this form: DDDD:BB:dd.f - -* When not using multi-functions (norid is set, or the firmware does not - support multi-functions): - - - There is only one function per domain. - - - The domain is set from the zPCI function's UID as defined during the - LPAR creation. - -* When using multi-functions (norid parameter is not set), - zPCI functions are addressed differently: - - - There is still only one bus per domain. - - - There can be up to 256 functions per bus. - - - The domain part of the address of all functions for - a multi-Function device is set from the zPCI function's UID as defined - in the LPAR creation for the function zero. - - - New functions will only be ready for use after the function zero - (the function with devfn 0) has been enumerated. |