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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/s390/CommonIO | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'Documentation/s390/CommonIO')
-rw-r--r-- | Documentation/s390/CommonIO | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO new file mode 100644 index 000000000000..a831d9ae5a5e --- /dev/null +++ b/Documentation/s390/CommonIO @@ -0,0 +1,109 @@ +S/390 common I/O-Layer - command line parameters and /proc entries +================================================================== + +Command line parameters +----------------------- + +* cio_msg = yes | no + + Determines whether information on found devices and sensed device + characteristics should be shown during startup, i. e. messages of the types + "Detected device 0.0.4711 on subchannel 0.0.0042" and "SenseID: Device + 0.0.4711 reports: ...". + + Default is off. + + +* 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 (0.0.abcd) or as hexadecimal + device numbers (0xabcd or abcd, for 2.4 backward compatibility). + You can use the 'all' keyword to ignore all devices. + The '!' operator will cause the I/O-layer to _not_ ignore a device. + The order on the command line is not important. + + 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. + + 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: Already known devices cannot be ignored. + + For example, if device 0.0.abcd is already known and all other devices + 0.0.a000-0.0.afff are not known, + "echo add 0.0.a000-0.0.accc, 0.0.af00-0.0.afff > /proc/cio_ignore" + will add 0.0.a000-0.0.abcc, 0.0.abce-0.0.accc and 0.0.af00-0.0.afff to the + list of ignored devices and skip 0.0.abcd. + + The devices can be specified either by bus id (0.0.abcd) or, for 2.4 backward + compatibilty, by the device number in hexadecimal (0xabcd or abcd). + + +* /proc/s390dbf/cio_*/ (S/390 debug feature) + + Some views generated by the debug feature to hold various debug outputs. + + - /proc/s390dbf/cio_crw/sprintf + Messages from the processing of pending channel report words (machine check + handling), which will also show when CONFIG_DEBUG_CRW is defined. + + - /proc/s390dbf/cio_msg/sprintf + Various debug messages from the common I/O-layer; generally, messages which + will also show when CONFIG_DEBUG_IO is defined. + + - /proc/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. + + The level of logging can be changed to be more or less verbose by piping to + /proc/s390dbf/cio_*/level a number between 0 and 6; see the documentation on + the S/390 debug feature (Documentation/s390/s390dbf.txt) for details. + +* 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. |