1S/390 common I/O-Layer - command line parameters and /proc entries 2================================================================== 3 4Command line parameters 5----------------------- 6 7* cio_msg = yes | no 8 9 Determines whether information on found devices and sensed device 10 characteristics should be shown during startup, i. e. messages of the types 11 "Detected device 0.0.4711 on subchannel 0.0.0042" and "SenseID: Device 12 0.0.4711 reports: ...". 13 14 Default is off. 15 16 17* cio_ignore = {all} | 18 {<device> | <range of devices>} | 19 {!<device> | !<range of devices>} 20 21 The given devices will be ignored by the common I/O-layer; no detection 22 and device sensing will be done on any of those devices. The subchannel to 23 which the device in question is attached will be treated as if no device was 24 attached. 25 26 An ignored device can be un-ignored later; see the "/proc entries"-section for 27 details. 28 29 The devices must be given either as bus ids (0.0.abcd) or as hexadecimal 30 device numbers (0xabcd or abcd, for 2.4 backward compatibility). 31 You can use the 'all' keyword to ignore all devices. 32 The '!' operator will cause the I/O-layer to _not_ ignore a device. 33 The command line is parsed from left to right. 34 35 For example, 36 cio_ignore=0.0.0023-0.0.0042,0.0.4711 37 will ignore all devices ranging from 0.0.0023 to 0.0.0042 and the device 38 0.0.4711, if detected. 39 As another example, 40 cio_ignore=all,!0.0.4711,!0.0.fd00-0.0.fd02 41 will ignore all devices but 0.0.4711, 0.0.fd00, 0.0.fd01, 0.0.fd02. 42 43 By default, no devices are ignored. 44 45 46/proc entries 47------------- 48 49* /proc/cio_ignore 50 51 Lists the ranges of devices (by bus id) which are ignored by common I/O. 52 53 You can un-ignore certain or all devices by piping to /proc/cio_ignore. 54 "free all" will un-ignore all ignored devices, 55 "free <device range>, <device range>, ..." will un-ignore the specified 56 devices. 57 58 For example, if devices 0.0.0023 to 0.0.0042 and 0.0.4711 are ignored, 59 - echo free 0.0.0030-0.0.0032 > /proc/cio_ignore 60 will un-ignore devices 0.0.0030 to 0.0.0032 and will leave devices 0.0.0023 61 to 0.0.002f, 0.0.0033 to 0.0.0042 and 0.0.4711 ignored; 62 - echo free 0.0.0041 > /proc/cio_ignore will furthermore un-ignore device 63 0.0.0041; 64 - echo free all > /proc/cio_ignore will un-ignore all remaining ignored 65 devices. 66 67 When a device is un-ignored, device recognition and sensing is performed and 68 the device driver will be notified if possible, so the device will become 69 available to the system. Note that un-ignoring is performed asynchronously. 70 71 You can also add ranges of devices to be ignored by piping to 72 /proc/cio_ignore; "add <device range>, <device range>, ..." will ignore the 73 specified devices. 74 75 Note: While already known devices can be added to the list of devices to be 76 ignored, there will be no effect on then. However, if such a device 77 disappears and then reappears, it will then be ignored. 78 79 For example, 80 "echo add 0.0.a000-0.0.accc, 0.0.af00-0.0.afff > /proc/cio_ignore" 81 will add 0.0.a000-0.0.accc and 0.0.af00-0.0.afff to the list of ignored 82 devices. 83 84 The devices can be specified either by bus id (0.0.abcd) or, for 2.4 backward 85 compatibility, by the device number in hexadecimal (0xabcd or abcd). 86 87 88* /proc/s390dbf/cio_*/ (S/390 debug feature) 89 90 Some views generated by the debug feature to hold various debug outputs. 91 92 - /proc/s390dbf/cio_crw/sprintf 93 Messages from the processing of pending channel report words (machine check 94 handling), which will also show when CONFIG_DEBUG_CRW is defined. 95 96 - /proc/s390dbf/cio_msg/sprintf 97 Various debug messages from the common I/O-layer; generally, messages which 98 will also show when CONFIG_DEBUG_IO is defined. 99 100 - /proc/s390dbf/cio_trace/hex_ascii 101 Logs the calling of functions in the common I/O-layer and, if applicable, 102 which subchannel they were called for, as well as dumps of some data 103 structures (like irb in an error case). 104 105 The level of logging can be changed to be more or less verbose by piping to 106 /proc/s390dbf/cio_*/level a number between 0 and 6; see the documentation on 107 the S/390 debug feature (Documentation/s390/s390dbf.txt) for details. 108 109* For some of the information present in the /proc filesystem in 2.4 (namely, 110 /proc/subchannels and /proc/chpids), see driver-model.txt. 111 Information formerly in /proc/irq_count is now in /proc/interrupts. 112