Commit 3952c8d4 authored by Cornelia Huck's avatar Cornelia Huck Committed by Martin Schwidefsky
Browse files

[S390] cio: Documentation update.


Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 6920c12a
......@@ -7,7 +7,7 @@
cds.txt
- s390 common device support (common I/O layer).
CommonIO
- common I/O layer command line parameters and /proc entries
- common I/O layer command line parameters, procfs and debugfs entries
config3270.sh
- example configuration for 3270 devices.
DASD
......
S/390 common I/O-Layer - command line parameters and /proc entries
==================================================================
S/390 common I/O-Layer - command line parameters, procfs and debugfs entries
============================================================================
Command line parameters
-----------------------
......@@ -7,9 +7,9 @@ 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: ...".
characteristics should be shown during startup or when new devices are
found, 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.
......@@ -26,8 +26,10 @@ Command line parameters
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).
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.
......@@ -81,31 +83,36 @@ Command line parameters
will add 0.0.a000-0.0.accc and 0.0.af00-0.0.afff to the list of ignored
devices.
The devices can be specified either by bus id (0.0.abcd) or, for 2.4 backward
compatibility, by the device number in hexadecimal (0xabcd or abcd).
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.
* 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
---------------
* /proc/s390dbf/cio_*/ (S/390 debug feature)
* /sys/kernel/debug/s390dbf/cio_*/ (S/390 debug feature)
Some views generated by the debug feature to hold various debug outputs.
- /proc/s390dbf/cio_crw/sprintf
- /sys/kernel/debug/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.
handling).
- /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.
- /sys/kernel/debug/s390dbf/cio_msg/sprintf
Various debug messages from the common I/O-layer, including messages
printed when cio_msg=yes.
- /proc/s390dbf/cio_trace/hex_ascii
- /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
/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.
/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.
......@@ -286,10 +286,10 @@ first:
timeout value
-EIO: the common I/O layer terminated the request due to an error state
If the concurrent sense flag in the extended status word in the irb is set, the
field irb->scsw.count describes the number of device specific sense bytes
available in the extended control word irb->scsw.ecw[0]. No device sensing by
the device driver itself is required.
If the concurrent sense flag in the extended status word (esw) in the irb is
set, the field erw.scnt in the esw describes the number of device specific
sense bytes available in the extended control word irb->scsw.ecw[]. No device
sensing by the device driver itself is required.
The device interrupt handler can use the following definitions to investigate
the primary unit check source coded in sense byte 0 :
......
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