17e9db9eaSCornelia HuckWhat: /sys/bus/css/devices/.../type 27e9db9eaSCornelia HuckDate: March 2008 37e9db9eaSCornelia HuckContact: Cornelia Huck <cornelia.huck@de.ibm.com> 47e9db9eaSCornelia Huck linux-s390@vger.kernel.org 57e9db9eaSCornelia HuckDescription: Contains the subchannel type, as reported by the hardware. 67e9db9eaSCornelia Huck This attribute is present for all subchannel types. 77e9db9eaSCornelia Huck 87e9db9eaSCornelia HuckWhat: /sys/bus/css/devices/.../modalias 97e9db9eaSCornelia HuckDate: March 2008 107e9db9eaSCornelia HuckContact: Cornelia Huck <cornelia.huck@de.ibm.com> 117e9db9eaSCornelia Huck linux-s390@vger.kernel.org 127e9db9eaSCornelia HuckDescription: Contains the module alias as reported with uevents. 137e9db9eaSCornelia Huck It is of the format css:t<type> and present for all 147e9db9eaSCornelia Huck subchannel types. 157e9db9eaSCornelia Huck 167e9db9eaSCornelia HuckWhat: /sys/bus/css/drivers/io_subchannel/.../chpids 177e9db9eaSCornelia HuckDate: December 2002 187e9db9eaSCornelia HuckContact: Cornelia Huck <cornelia.huck@de.ibm.com> 197e9db9eaSCornelia Huck linux-s390@vger.kernel.org 207e9db9eaSCornelia HuckDescription: Contains the ids of the channel paths used by this 217e9db9eaSCornelia Huck subchannel, as reported by the channel subsystem 227e9db9eaSCornelia Huck during subchannel recognition. 237e9db9eaSCornelia Huck Note: This is an I/O-subchannel specific attribute. 247e9db9eaSCornelia HuckUsers: s390-tools, HAL 257e9db9eaSCornelia Huck 267e9db9eaSCornelia HuckWhat: /sys/bus/css/drivers/io_subchannel/.../pimpampom 277e9db9eaSCornelia HuckDate: December 2002 287e9db9eaSCornelia HuckContact: Cornelia Huck <cornelia.huck@de.ibm.com> 297e9db9eaSCornelia Huck linux-s390@vger.kernel.org 307e9db9eaSCornelia HuckDescription: Contains the PIM/PAM/POM values, as reported by the 317e9db9eaSCornelia Huck channel subsystem when last queried by the common I/O 3225985edcSLucas De Marchi layer (this implies that this attribute is not necessarily 337e9db9eaSCornelia Huck in sync with the values current in the channel subsystem). 347e9db9eaSCornelia Huck Note: This is an I/O-subchannel specific attribute. 357e9db9eaSCornelia HuckUsers: s390-tools, HAL 36*ebc3d179SCornelia Huck 37*ebc3d179SCornelia HuckWhat: /sys/bus/css/devices/.../driver_override 38*ebc3d179SCornelia HuckDate: June 2019 39*ebc3d179SCornelia HuckContact: Cornelia Huck <cohuck@redhat.com> 40*ebc3d179SCornelia Huck linux-s390@vger.kernel.org 41*ebc3d179SCornelia HuckDescription: This file allows the driver for a device to be specified. When 42*ebc3d179SCornelia Huck specified, only a driver with a name matching the value written 43*ebc3d179SCornelia Huck to driver_override will have an opportunity to bind to the 44*ebc3d179SCornelia Huck device. The override is specified by writing a string to the 45*ebc3d179SCornelia Huck driver_override file (echo vfio-ccw > driver_override) and 46*ebc3d179SCornelia Huck may be cleared with an empty string (echo > driver_override). 47*ebc3d179SCornelia Huck This returns the device to standard matching rules binding. 48*ebc3d179SCornelia Huck Writing to driver_override does not automatically unbind the 49*ebc3d179SCornelia Huck device from its current driver or make any attempt to 50*ebc3d179SCornelia Huck automatically load the specified driver. If no driver with a 51*ebc3d179SCornelia Huck matching name is currently loaded in the kernel, the device 52*ebc3d179SCornelia Huck will not bind to any driver. This also allows devices to 53*ebc3d179SCornelia Huck opt-out of driver binding using a driver_override name such as 54*ebc3d179SCornelia Huck "none". Only a single driver may be specified in the override, 55*ebc3d179SCornelia Huck there is no support for parsing delimiters. 56*ebc3d179SCornelia Huck Note that unlike the mechanism of the same name for pci, this 57*ebc3d179SCornelia Huck file does not allow to override basic matching rules. I.e., 58*ebc3d179SCornelia Huck the driver must still match the subchannel type of the device. 59