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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/s390/CommonIO
downloadlinux-linaro-stable-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
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!
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+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.