summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/sysfs-bus-css
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/ABI/testing/sysfs-bus-css
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-css')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-css61
1 files changed, 61 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-css b/Documentation/ABI/testing/sysfs-bus-css
new file mode 100644
index 000000000..12a733fe3
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-css
@@ -0,0 +1,61 @@
+What: /sys/bus/css/devices/.../type
+Date: March 2008
+Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
+ linux-s390@vger.kernel.org
+Description: Contains the subchannel type, as reported by the hardware.
+ This attribute is present for all subchannel types.
+
+What: /sys/bus/css/devices/.../modalias
+Date: March 2008
+Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
+ linux-s390@vger.kernel.org
+Description: Contains the module alias as reported with uevents.
+ It is of the format css:t<type> and present for all
+ subchannel types.
+
+What: /sys/bus/css/drivers/io_subchannel/.../chpids
+Date: December 2002
+Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
+ linux-s390@vger.kernel.org
+Description: Contains the ids of the channel paths used by this
+ subchannel, as reported by the channel subsystem
+ during subchannel recognition.
+
+ Note: This is an I/O-subchannel specific attribute.
+Users: s390-tools, HAL
+
+What: /sys/bus/css/drivers/io_subchannel/.../pimpampom
+Date: December 2002
+Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
+ linux-s390@vger.kernel.org
+Description: Contains the PIM/PAM/POM values, as reported by the
+ channel subsystem when last queried by the common I/O
+ layer (this implies that this attribute is not necessarily
+ in sync with the values current in the channel subsystem).
+
+ Note: This is an I/O-subchannel specific attribute.
+Users: s390-tools, HAL
+
+What: /sys/bus/css/devices/.../driver_override
+Date: June 2019
+Contact: Cornelia Huck <cohuck@redhat.com>
+ linux-s390@vger.kernel.org
+Description: This file allows the driver for a device to be specified. When
+ specified, only a driver with a name matching the value written
+ to driver_override will have an opportunity to bind to the
+ device. The override is specified by writing a string to the
+ driver_override file (echo vfio-ccw > driver_override) and
+ may be cleared with an empty string (echo > driver_override).
+ This returns the device to standard matching rules binding.
+ Writing to driver_override does not automatically unbind the
+ device from its current driver or make any attempt to
+ automatically load the specified driver. If no driver with a
+ matching name is currently loaded in the kernel, the device
+ will not bind to any driver. This also allows devices to
+ opt-out of driver binding using a driver_override name such as
+ "none". Only a single driver may be specified in the override,
+ there is no support for parsing delimiters.
+
+ Note that unlike the mechanism of the same name for pci, this
+ file does not allow to override basic matching rules. I.e.,
+ the driver must still match the subchannel type of the device.