If the error is corrected, the temporary error is not recorded and
control is returned toDMKIOS with all error flags off. When ERP has determined a permanent error situation or successfully
recoveredfrom an error, all auxiliary storage obtained for recovery CCWs, buffers, and IOERBLOKs is freed before a return is made to DMKIOS (see Figure 22 for a summary of the lOB indicators). Also, the
statistical counters for3270 are updated.
The Attached Processor Environment
Attached processor support is requested by specifyingAP=YES on the SYSCOR macro. For a complete description of system generation
considerations, see CP Initialization for the Attached Processor Qf QEeration, has a detailed discussion of
prefixing that is necessary for understanding the initialization done
for the attached processor.PROCESSOR ADDRESSES The CP initialization routine, DMKCPI, begins normal processing by
storing the physical,main processor address --usually X'OO' -- in the IPUADDR field in the PSA at location absolute zero. (Prefixing has not
yet been established.) The logical processor address is computed by
doing a logicalOR of the physical address with X'40' and is stored in
thePSI in LPUADDR. The logical value is used by the CP LOCK manager to
avoid using a zero value. The physical value is used for signaling
between thetwo processors.
IfAP=YES was coded on the SYSCOR macro, DMKCPI uses the SIGP function to see if the attached processor is available. If so, its
physical and logical addresses are stored in thePSA in IPUIDDRX and LPUADDRX, respectively. If the attached processor is not available, APUBOBLB is set to 1. If the multi-processing option is installed, message DMKCPI959w is sent to the operator. PSA SETUP The top two 4K pages of storage are marked (in the CORTIBLE) as being CP-owned and are used as the PSAs for the two processors. The addresses
of thesetwo pages are stored at PREFIXA and PREFIXB in the PSI at
location absolute zero.DMKAPI copies the information from the PSI at
location absolute zero to thenew PSA locations. In the PSI designated
for the attached processor,PREFIX! and PREFIXB are switched. Thus, on
either processorPREFIXA always represents the current processor and PREPIXB the other processor. The values of IPUADDR, LPUADDR, IPUIDDRX, and LPUADDRX are also switched so that IPUADDR and LPUIDDR always
contain the processor addresses of the current processor andIPUADDRX and LPUADDRX contain the other processor addresses.
1-172IB! VM/370 System Logic and Problem Determination--Volume 1
control is returned to
recovered
statistical counters for
The Attached Processor Environment
Attached processor support is requested by specifying
considerations, see
prefixing that is necessary for understanding the initialization done
for the attached processor.
storing the physical,
yet been established.) The logical processor address is computed by
doing a logical
the
avoid using a zero value. The physical value is used for signaling
between the
If
physical and logical addresses are stored in the
of these
location absolute zero.
location absolute zero to the
for the attached processor,
either processor
contain the processor addresses of the current processor and
1-172