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Diffstat (limited to 'Documentation/s390/CommonIO')
| -rw-r--r-- | Documentation/s390/CommonIO | 123 |
1 files changed, 0 insertions, 123 deletions
diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO deleted file mode 100644 index d378cba6645..00000000000 --- a/Documentation/s390/CommonIO +++ /dev/null @@ -1,123 +0,0 @@ -S/390 common I/O-Layer - command line parameters, procfs and debugfs entries -============================================================================ - -Command line parameters ------------------------ - -* ccw_timeout_log - - Enable logging of debug information in case of ccw device timeouts. - -* cio_ignore = {all} | - {<device> | <range of devices>} | - {!<device> | !<range of devices>} - - The given devices will be ignored by the common I/O-layer; no detection - and device sensing will be done on any of those devices. The subchannel to - which the device in question is attached will be treated as if no device was - attached. - - An ignored device can be un-ignored later; see the "/proc entries"-section for - details. - - The devices must be given either as bus ids (0.x.abcd) or as hexadecimal - device numbers (0xabcd or abcd, for 2.4 backward compatibility). If you - give a device number 0xabcd, it will be interpreted as 0.0.abcd. - - You can use the 'all' keyword to ignore all devices. - The '!' operator will cause the I/O-layer to _not_ ignore a device. - The command line is parsed from left to right. - - For example, - cio_ignore=0.0.0023-0.0.0042,0.0.4711 - will ignore all devices ranging from 0.0.0023 to 0.0.0042 and the device - 0.0.4711, if detected. - As another example, - cio_ignore=all,!0.0.4711,!0.0.fd00-0.0.fd02 - will ignore all devices but 0.0.4711, 0.0.fd00, 0.0.fd01, 0.0.fd02. - - By default, no devices are ignored. - - -/proc entries -------------- - -* /proc/cio_ignore - - Lists the ranges of devices (by bus id) which are ignored by common I/O. - - You can un-ignore certain or all devices by piping to /proc/cio_ignore. - "free all" will un-ignore all ignored devices, - "free <device range>, <device range>, ..." will un-ignore the specified - devices. - - For example, if devices 0.0.0023 to 0.0.0042 and 0.0.4711 are ignored, - - echo free 0.0.0030-0.0.0032 > /proc/cio_ignore - will un-ignore devices 0.0.0030 to 0.0.0032 and will leave devices 0.0.0023 - to 0.0.002f, 0.0.0033 to 0.0.0042 and 0.0.4711 ignored; - - echo free 0.0.0041 > /proc/cio_ignore will furthermore un-ignore device - 0.0.0041; - - echo free all > /proc/cio_ignore will un-ignore all remaining ignored - devices. - - When a device is un-ignored, device recognition and sensing is performed and - the device driver will be notified if possible, so the device will become - available to the system. Note that un-ignoring is performed asynchronously. - - You can also add ranges of devices to be ignored by piping to - /proc/cio_ignore; "add <device range>, <device range>, ..." will ignore the - specified devices. - - Note: While already known devices can be added to the list of devices to be - ignored, there will be no effect on then. However, if such a device - disappears and then reappears, it will then be ignored. To make - known devices go away, you need the "purge" command (see below). - - For example, - "echo add 0.0.a000-0.0.accc, 0.0.af00-0.0.afff > /proc/cio_ignore" - will add 0.0.a000-0.0.accc and 0.0.af00-0.0.afff to the list of ignored - devices. - - You can remove already known but now ignored devices via - "echo purge > /proc/cio_ignore" - All devices ignored but still registered and not online (= not in use) - will be deregistered and thus removed from the system. - - The devices can be specified either by bus id (0.x.abcd) or, for 2.4 backward - compatibility, by the device number in hexadecimal (0xabcd or abcd). Device - numbers given as 0xabcd will be interpreted as 0.0.abcd. - -* /proc/cio_settle - - A write request to this file is blocked until all queued cio actions are - handled. This will allow userspace to wait for pending work affecting - device availability after changing cio_ignore or the hardware configuration. - -* For some of the information present in the /proc filesystem in 2.4 (namely, - /proc/subchannels and /proc/chpids), see driver-model.txt. - Information formerly in /proc/irq_count is now in /proc/interrupts. - - -debugfs entries ---------------- - -* /sys/kernel/debug/s390dbf/cio_*/ (S/390 debug feature) - - Some views generated by the debug feature to hold various debug outputs. - - - /sys/kernel/debug/s390dbf/cio_crw/sprintf - Messages from the processing of pending channel report words (machine check - handling). - - - /sys/kernel/debug/s390dbf/cio_msg/sprintf - Various debug messages from the common I/O-layer. - - - /sys/kernel/debug/s390dbf/cio_trace/hex_ascii - Logs the calling of functions in the common I/O-layer and, if applicable, - which subchannel they were called for, as well as dumps of some data - structures (like irb in an error case). - - The level of logging can be changed to be more or less verbose by piping to - /sys/kernel/debug/s390dbf/cio_*/level a number between 0 and 6; see the - documentation on the S/390 debug feature (Documentation/s390/s390dbf.txt) - for details. |