Copyright, IBM Corp. 2020
-command line parameters and debugfs entries
+Command line parameters and debugfs entries
===========================================
Command line parameters
* nomio
- Do not use MIO instructions.
+ Do not use PCI Mapped I/O (MIO) instructions.
* norid
debugfs entries
---------------
-* /sys/kernel/debug/s390dbf/pci_*/ (S/390 debug feature)
+The S/390 debug feature (s390dbf) generates views to hold various debug results in sysfs directories of the form:
- Some views generated by the debug feature to hold various debug outputs.
+ * /sys/kernel/debug/s390dbf/pci_*/
+
+For example:
- /sys/kernel/debug/s390dbf/pci_msg/sprintf
- Messages from the processing of PCI events like machine check handling
- and setting of global functionality like UID checking.
+ Holds messages from the processing of PCI events, like machine check handling
+ and setting of global functionality, like UID checking.
- The level of logging can be changed to be more or less verbose by piping to
- /sys/kernel/debug/s390dbf/pci_*/level a number between 0 and 6; see the
- documentation on the S/390 debug feature (Documentation/s390/s390dbf.rst)
- for details.
+ 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
=============
-Specific entries, or entries specificities for zPCI functions.
+Entries specific to zPCI functions and entries that hold zPCI information.
* /sys/bus/pci/slots/XXXXXXXX
- The slot entries are setup using the FID (Function Identifier) of the
+ The slot entries are set up using the function identifier (FID) of the
PCI function.
- /sys/bus/pci/slots/XXXXXXXX/power
- A physical function currently supporting virtual function can not be
- powered-off until all virtual-function have been removed with
+ 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
- zPCI function identifier unique for the complete Z System.
- It define uniquely a function in the system.
+ 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 may be useful for debuging.
+ Low-level identifier used for a configured PCI function.
+ It might be useful for debuging.
- pchid
- Model dependent location of the I/O adapter.
+ Model-dependent location of the I/O adapter.
- pfgid
- PCI Function Group ID, functions sharing identical functionality
- are using a common identifier.
- A PCI group defines interrupts, IOMMU, IOTLB and DMA specifics.
+ 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.
+ The virtual function number, from 1 to N for virtual functions,
0 for physical functions.
- pft
- PCI function type specifies the type of the PCI function.
+ The PCI function type
- port
- The port correspond to the physical port the function is attached to.
- It also gives an indication on the physical function a virtual function
+ 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 UID, Unique Identifier is defined when configuring a LPAR and is
- unique inside an LPAR.
+ The unique identifier (UID) is defined when configuring an LPAR and is
+ unique in the LPAR.
- pfip/segmentX
- The segments are used to determine the isolation of a function.
- They corresponds to the physical path to the function.
- The more the segment are different the more the functions are isolated.
+ 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 is made of 4 parts: domain, bus, device and function,
-like in DDDD:BB:dd.f
+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 firmware does not support
- multi-functions)
+* 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
+ - The domain is set from the zPCI function's UID as defined during the
LPAR creation.
- - Addresses look like DDDD:00:00.0
-
-* When using multi-functions (norid parameter is not set), there are some
- change in the way zPCI functions are addressed:
+* 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 of all functions for
+ - 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 to be used after the function zero
+ - New functions will only be ready for use after the function zero
(the function with devfn 0) has been enumerated.
projects / linux-2.6-microblaze.git / blobdiff