STRUCT IRB

Section: The ccw bus (9)
Updated: February 2011
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NAME

struct_irb - interruption response block

SYNOPSIS

struct irb {
  union scsw scsw;
  union esw;
  __u8 ecw[32];
};

MEMBERS

scsw

: subchannel status word

esw

: extened status word, 4 formats

ecw[32]

: extended control word

DESCRIPTION

The irb that is handed to the device driver when an interrupt occurs. For solicited interrupts, the common I/O layer already performs checks whether a field is valid; a field not being valid is always passed as 0. If a unit check occured, ecw may contain sense data; this is retrieved by the common I/O layer itself if the device doesn't support concurrent sense (so that the device driver never needs to perform basic sene itself). For unsolicited interrupts, the irb is passed as-is (expect for sense data, if applicable).

AUTHOR

Cornelia Huck <cornelia.huck@de.ibm.com>