patch-2.4.22 linux-2.4.22/Documentation/s390/CommonIO
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- Lines: 67
- Date:
2003-08-25 04:44:39.000000000 -0700
- Orig file:
linux-2.4.21/Documentation/s390/CommonIO
- Orig date:
2001-10-11 09:04:57.000000000 -0700
diff -urN linux-2.4.21/Documentation/s390/CommonIO linux-2.4.22/Documentation/s390/CommonIO
@@ -21,7 +21,8 @@
Default is on.
-* cio_ignore = <range of device numbers>, <range of device numbers>, ...
+* cio_ignore = <device number> | <range of device numbers>,
+ <device number> | <range of device numbers>, ...
The given device numbers 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
@@ -55,14 +56,22 @@
* /proc/subchannels
- Shows for each subchannel
- - device number
- - device type/model and if applicable control unit type/model
- - whether the device is in use
- - path installed mask, path available mask, path operational mask and last
- path used mask
- - the channel path IDs (chpids)
+ This entry shows information on a per-subchannel basis.
+ The data is ordered in the following way:
+
+ - device number
+ - subchannel number
+ - device type/model (if applicable; if not, this is empty) and control unit
+ type/model
+ - whether the device is in use (i. e. a device driver has requested ownership
+ and registered an interrupt handler)
+ - path installed mask (PIM), as reflected by last store subchannel
+ - path available mask (PAM), as reflected by last store subchannel
+ - path operational mask (POM), as reflected by last store subchannel
+ - the channel path IDs (CHPIDs)
+
+ All fields are separated by spaces, the chpids are in blocks of four chpids.
* /proc/deviceinfo/
@@ -137,3 +146,26 @@
This entry counts how many times s390_process_IRQ has been called for each
CPU. This info is in /proc/interrupts on other architectures.
+
+* /proc/chpids
+
+ This entry will only show up if you specified CONFIG_CHSC=y during kernel
+ config.
+
+ This entry serves a dual purpose:
+
+ - show which chpids are currently known to Linux and their status (online,
+ logically offline),
+
+ - toggling known chpids logically online/offline.
+
+ To toggle a known chpid logically offline, do an
+ echo off <chpid> > /proc/chpids
+ <chpid> is interpreted as hex, even if you omit the '0x'.
+ The chpid will be treated by Linux as if it were not online, which can mean
+ some devices will become unavailable.
+
+ You can toggle a logically offline chpid online again by
+ echo on <chpid> > /proc/chpids
+ If devices became unavailable by toggling the chpid logically offline, they
+ will become available again after you toggle the chpid online again.
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