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 4711 on subchannel 42" and "SenseID: Device 4711 reports: ...". 12 13 Default is off. 14 15 16* cio_notoper_msg = yes | no 17 18 Determines whether messages of the type "Device 4711 became 'not operational'" 19 should be shown during startup; after startup, they will always be shown. 20 21 Default is on. 22 23 24* cio_ignore = <range of device numbers>, <range of device numbers>, ... 25 26 The given device numbers will be ignored by the common I/O-layer; no detection 27 and device sensing will be done on any of those devices. The subchannel to 28 which the device in question is attached will be treated as if no device was 29 attached. 30 31 An ignored device can be un-ignored later; see the "/proc entries"-section for 32 details. 33 34 The device numbers must be given hexadecimal. 35 36 For example, 37 cio_ignore=0x23-0x42,0x4711 38 will ignore all devices with device numbers ranging from 23 to 42 and the 39 device with device number 4711, if detected. 40 41 By default, no devices are ignored. 42 43 44* cio_proc_devinfo = yes | no 45 46 Determines whether the entries under /proc/deviceinfo/ (see below) should be 47 created. Since there are problems with systems with many devices attached, I 48 made it configurable. 49 50 Until the problems are dealt with, default is off. 51 52 53/proc entries 54------------- 55 56* /proc/subchannels 57 58 Shows for each subchannel 59 - device number 60 - device type/model and if applicable control unit type/model 61 - whether the device is in use 62 - path installed mask, path available mask, path operational mask and last 63 path used mask 64 - the channel path IDs (chpids) 65 66 67* /proc/deviceinfo/ 68 69 Shows in subdirectories for each device some characteristics: 70 - /proc/deviceinfo/<devno>/chpids: 71 the channel path IDs 72 - /proc/deviceinfo/<devno>/in_use: 73 whether the device is in use 74 - /proc/deviceinfo/<devno>/sensedata: 75 the device type/model and if applicable control unit type/model of the 76 device 77 78 NOTE: Since the number of inodes which can be dynamically allocated by procfs 79 is limited, device entries will only be created up to a magic number of 80 devices. The kernel will utter a warning that not all entries can be 81 created. In this case, you shouldn't use "cio_proc_devinfo=yes" (see 82 above). 83 84* /proc/cio_ignore 85 86 Lists the ranges of device numbers which are ignored by common I/O. 87 88 You can un-ignore certain or all devices by piping to /proc/cio_ignore. 89 "free all" will un-ignore all ignored devices, 90 "free <devnorange>, <devnorange>, ..." will un-ignore the specified devices. 91 92 For example, if devices 23 to 42 and 4711 are ignored, 93 - echo free 0x30-0x32 > /proc/cio_ignore 94 will un-ignore devices 30 to 32 and will leave devices 23 to 2F, 33 to 42 95 and 4711 ignored; 96 - echo free 0x41 > /proc/cio_ignore will furthermore un-ignore device 41; 97 - echo free all > /proc/cio_ignore will un-ignore all remaining ignored 98 devices. 99 100 When a device is un-ignored, device recognition and sensing is performed and 101 the device driver will be notified if possible, so the device will become 102 available to the system. 103 104 You can also add ranges of devices to be ignored by piping to 105 /proc/cio_ignore; "add <devnorange>, <devnorange>, ..." will ignore the 106 specified devices. 107 108 Note: Already known devices cannot be ignored; this also applies to devices 109 which are gone after a machine check. 110 111 For example, if device abcd is already known and all other devices a000-afff 112 are not known, "echo add 0xa000-0xaccc, 0xaf00-0xafff > /proc/cio_ignore" 113 will add af00-afff to the list of ignored devices and skip a000-accc. 114 115 116* /proc/s390dbf/cio_*/ (S/390 debug feature) 117 118 Some views generated by the debug feature to hold various debug outputs. 119 120 - /proc/s390dbf/cio_crw/sprintf 121 Messages from the processing of pending channel report words (machine check 122 handling), which will also show when CONFIG_DEBUG_CRW is defined. 123 124 - /proc/s390dbf/cio_msg/sprintf 125 Various debug messages from the common I/O-layer; generally, messages which 126 will also show when CONFIG_DEBUG_IO is defined. 127 128 - /proc/s390dbf/cio_trace/hex_ascii 129 Logs the calling of functions in the common I/O-layer and, if applicable, 130 which subchannel they were called for. 131 132 The level of logging can be changed to be more or less verbose by piping to 133 /proc/s390dbf/cio_*/level a number between 0 and 6; see the documentation on 134 the S/390 debug feature (Documentation/s390/s390dbf.txt) for details. 135 136* /proc/irq_count 137 138 This entry counts how many times s390_process_IRQ has been called for each 139 CPU. This info is in /proc/interrupts on other architectures. 140